System Alert! Add Extension" pop ads: what it is and how to remove it
"System Alert! Add Extension" virus triggers fake alerts urging netizens to install shady extensions.
Facts checked October 7, 2026. Removal steps tested on Windows 11 (26H2) and checked against Microsoft's and the browser makers' current documentation. Sections marked as our earlier report are the original text: they describe the threat as it was then and have not been reviewed since. The 2026 status, the removal steps and the questions are current.
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System Alert! Add Extension" pop ads: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Distribution | Not recorded in the old report |
| Damage | Not recorded in the old report |
| Name | System Alert! Add Extension" pop |
| Type | Adware extension |
| Symptoms | An unknown program in Installed apps |
| Removal | Scan the PC with security software to find and remove the malware and anything installed with it. Fortect scans Windows for malware and repairs the system files and settings it damaged. Remove it nowTo use the full-featured product, you have to purchase a license for Fortect. The scan is free. |
Show 4 more facts
| Evidence | 3 write-ups by security sites; details still limited |
|---|---|
| Program | System Alert! Add Extension" pop |
| First seen | 7 July 2017 |
| Facts checked | 7 October 2026 |
Is System Alert! Add Extension" pop ads dangerous?
From our report of Jul 2017 · not reviewed since
"System Alert! Add Extension" alerts are more than an annoyance
"System Alert!
Add Extension" virus triggers fake alerts urging netizens to install shady extensions. Most likely, you may encounter them while getting redirected by a movie streaming site. The messages ask to install a browser extension in order to assure browsing safety. Enabling the installation this suspicious extension may lead to hijacked web browser, installation of an ad-supported application or even malicious program.
"System Alert! Add Extension" might prevent from closing the misleading website. But you should not agree to install the offered extension, click "Cancel" button or mark "Prevent this page from creating additional dialogs" option.
It's a trick. You will be still forced to install the extension.
In some cases, this notification is followed by a voice message that says: "Click Add button to install the extension." No matter how convincing or threatening robot's voice is, you should not do what you are asked.
Once you end up on such website, close the browser's tab. If you cannot do it, you should force-quit and then scan the computer with anti-malware/anti-spyware. The security program, such as , will help to remove "System Alert! Add Extension" and forget about other negative features of the adware.
As we have mentioned, redirects to this malicious site are usually initiated by an ad-supported program. This potentially unwanted program (PUP) spread in software bundles and enters the system silently. Once it gets inside, it might alter few settings in Windows and web browsers.
Apart from promoting unknown extension, this program might also:
"System Alert! Add Extension" removal is also recommended because adware might deliver third-party ads that lead to infected, phishing or tech support scam websites. Thus, you can easily suffer from cyber criminals, reveal your personal information or let malware to your PC.
Currently, the majority of users who have dealt with this cyber parasite the most are the United States, Canada, and the United Kingdom. However, it might spread further to other parts of the world too.
- apply a virtual layer to display third-party commercial content;
- redirect to promotional websites;
- turn text into hyperlinks;
- deliver fake security alters;
- deliver fake software updates;
- track information about users;
- modify browser's homepage or/and search engine.
From our report of Jul 2017 · not reviewed since
The reason behind fake system messages is adware program
When you're browsing through adult-themed websites or watch movies on illegal video streaming sites, you might receive "System Alert!
Add Extension" pop-up any minute. Obviously, you should not use such sites in order to protect yourself from similar cyber infections.
However, redirects to the misleading site are most of the time caused by an adware program. If you have recently installed freeware or shareware, this undesired app may have sneak inside too. It may have happened if you have installed a program under Quick/Recommended setup.
The problem is that these settings do not openly disclose about third-party apps that may have been included in the software package. Thus, relying on this method, you always risk to let PUPs to get inside your device.
To avoid "System Alert! Add Extension" hijack and similar problems, you should always install new software using Advanced/Custom settings. The most important task is to reject installation of "additional downloads" by unmarking pre-selected entries.
How to remove System Alert! Add Extension" pop ads
How to remove the System Alert! Add Extension" pop extension
Do the browser steps in every browser and profile on the PC, then check Windows for the program that installed the extension.
Step 1: Remove extensions you did not add
System Alert! Add Extension" pop often works through an extension, so go through the extension list of each browser:
chrome://extensionsedge://extensions- Extensions and themes in Firefox
Switch suspicious extensions off one at a time and reload the page where the problem shows, then remove the one that stops it, and any other you did not add.
Remember the other browsers and profiles on the PC. If Remove is missing or greyed out, a policy forces the extension, which the policy step deals with. Windows 11 and Windows 10 show the same pages.
Chrome on Windows 11: More > Extensions > Manage extensions. Full procedure with screenshots: Remove a browser extension
Step 2: Uninstall System Alert! Add Extension" pop
Open Settings > Apps > Installed apps in Windows 11, or Settings > Apps > Apps & features in Windows 10. Sort the list by install date and find System Alert!
Add Extension" pop, then choose Uninstall from the three-dot menu next to it (in Windows 10, click the entry and then Uninstall).
Remove anything else installed on the same day that you do not recognise, because such programs usually arrive together in one installer. If the uninstaller opens a browser page with an offer or a survey, close it: the program is removed either way.
Full procedure with screenshots: Uninstall a program or app in Windows On uGetFix
Step 3: Reset the browser
Finish the browser part with a reset, which puts the search engine, start page, new tab page and site permissions back to their defaults and switches extensions off. Chrome: Settings > Reset settings > Restore settings to their original defaults.
Edge: Settings > Reset settings. Firefox: Help > More troubleshooting information > Refresh Firefox, which also removes its extensions. Your bookmarks and saved passwords are kept, and the menus are the same on Windows 11 and Windows 10.
Chrome on Windows 11: Settings > Reset settings. Full procedure with screenshots: Reset a browser and fix a hijacked search engine
Step 4: Scan the PC, then run the offline scan
Open Windows Security > Virus & threat protection > Scan options, run a Full scan and remove everything it finds. Then select Microsoft Defender Antivirus (offline scan) and click Scan now: the PC restarts and scans before Windows loads, which finds files that hide while Windows runs.
Save your work first, because the offline scan takes about 15 minutes. Both scans are built into Windows 11 and Windows 10, and a second scanner from another vendor is a useful extra opinion.
Windows 11: Windows Security > Virus & threat protection > Scan options. Full procedure with screenshots: Run a Microsoft Defender Offline scan
Instructions for each browser and system
The detailed steps for every browser and system this guide covers. Open the one you use.
Uninstall from Windows
Follow the steps below to find and delete adware program that is responsible for delivering "System Alert! Add Extension." Make sure that any adware-related entries haven't been left on the system. Then check the list of Chrome's extensions and make sure that any unknown add-ons haven't been installed.
Uninstall from Windows 10/8:
- Type Control Panel into the Windows search box and open the result.
- Under Programs, select Uninstall a program.
Uninstall from Windows 7/XP:
- Click on Windows Start > Control Panel (Windows XP users should click on Add/Remove Programs).
- In Control Panel, select Programs > Uninstall a program.
Remove the unwanted program:
- In the Programs and Features window, look for any recently installed suspicious entries, select them, and click Uninstall.
- If User Account Control appears, click Yes to confirm, then complete the removal.
Remove from Google Chrome
Open Chrome's extensions. Carefully look through the list. If you find some unknown extensions that you do not remember installing, remove them immediately. There's no doubt that they are related to "System Alert! Add Extension" adware. Finally, reset the browser in order to get rid of tracking cookies and other virus-related components.
Delete malicious extensions from Google Chrome:
- Open Google Chrome, click on the Menu (three vertical dots at the top-right corner) and select More tools > Extensions.
- In the newly opened window, you will see all the installed extensions. Uninstall all suspicious extensions related to the unwanted program by clicking Remove.
Clear cache and web data from Chrome:
- Click on Menu and pick Settings.
- Under Privacy and security, select Clear browsing data.
- Select Browsing history, Cookies and other site data, as well as Cached images and files.
- Click Clear data.
Change your homepage:
- Click menu and choose Settings.
- Look for a suspicious site in the On startup section.
- Click on Open a specific or set of pages and click on three dots to find the Remove option.
Reset Google Chrome:
If the previous methods did not help you, reset Google Chrome to eliminate all the unwanted components:
- Click on Menu and select Settings.
- In the Settings, scroll down and click Advanced.
- Scroll down and locate Reset and clean up section.
- Now click Restore settings to their original defaults.
- Confirm with Reset settings.
Remove from Microsoft Edge
Delete unwanted extensions from MS Edge:
- Select Menu (three horizontal dots at the top-right of the browser window) and pick Extensions.
- From the list, pick the extension and click on the Gear icon.
- Click Remove.
Clear cookies and other browser data:
- Click on the Menu (three horizontal dots at the top-right of the browser window) and select Settings > Privacy, search, and services..
- Under Clear browsing data, pick Choose what to clear.
- Select Cookies and other site data and Cached images and files. (apart from passwords, although you might want to include Media licenses as well, if applicable) and click on Clear.
Restore new tab and homepage settings:
- Click the menu icon and choose Settings.
- Then find On startup section.
- Click Remove next to any suspicious startup page.
Reset MS Edge if the above steps did not work:
- Press on Ctrl + Shift + Esc to open Task Manager.
- Click on More details arrow at the bottom of the window.
- Select Details tab.
- Now scroll down and locate every entry with Microsoft Edge name in it. Right-click on each of them and select End Task to stop MS Edge from running.
Delete extensions from MS Edge (Chromium):
- Open Edge and click select Settings > Extensions.
- Delete unwanted extensions by clicking Remove.
Clear cache and site data:
- Click on Menu and go to Settings.
- Select Privacy, search and services.
- Under Clear browsing data, pick Choose what to clear.
- Under Time range, pick All time.
- Select Clear now.
Reset Chromium-based MS Edge:
- Click on Menu and select Settings.
- On the left side, pick Reset settings.
- Select Restore settings to their default values.
- Confirm with Reset.
- This will disable extensions and reset startup pages but will not delete bookmarks, saved passwords, or browsing history.
Remove from Mozilla Firefox (FF)
Remove dangerous extensions:
- Open Mozilla Firefox browser and click on the Menu (three horizontal lines at the top-right of the window).
- Select Add-ons.
- In here, select the unwanted extension and click Remove.
Reset the homepage:
- Click three horizontal lines at the top right corner to open the menu.
- Choose Settings.
- Under Home, set your preferred homepage and new tab settings.
Clear cookies and site data:
- Click Menu and pick Settings.
- Go to Privacy & Security section.
- Scroll down to locate Cookies and Site Data.
- Click on Clear Data...
- Select Cookies and Site Data and Temporary cached files and pages, then click Clear.
Reset Mozilla Firefox
If clearing the browser as explained above did not help, reset Mozilla Firefox:
- Open Mozilla Firefox browser and click the Menu.
- Go to Help and then choose Troubleshooting Information.
- Under Give Firefox a tune up section, click on Refresh Firefox...
- Once the pop-up shows up, confirm the action by pressing on Refresh Firefox.
Delete from Safari
Remove dangerous extensions:
- Open Safari, click Safari in the menu at the top-left of the screen, and select Preferences.
- Go to the Extensions tab, look for any suspicious entries, and click Uninstall to remove them.
Clear history and website data:
- Click Safari in the menu and pick Clear History.
- Set Clear to all history and confirm with Clear History.
Reset Safari:
- Click Safari in the menu and select Preferences > Advanced.
- Enable Show Develop menu in menu bar.
- From the menu bar, click Develop and select Empty Caches.
Delete from macOS
Remove the unwanted application:
- From the menu bar, select Go > Applications.
- In the Applications folder, look for any suspicious entries, then drag them to Trash (or right-click and pick Move to Trash).
Delete leftover files and folders:
- Select Go > Go to Folder.
- Enter /Library/Application Support and remove any suspicious folders related to the unwanted program.
- Repeat the same check in the /Library/LaunchAgents and /Library/LaunchDaemons folders, deleting any suspicious entries.
- Finally, empty the Trash to permanently remove the leftovers.
Reset Internet Explorer
Remove dangerous add-ons:
- Open Internet Explorer, click on the Gear icon (IE menu) on the top-right corner of the browser
- Pick Manage Add-ons.
- You will see a Manage Add-ons window. Here, look for suspicious plugins. Click on these entries and select Disable.
Change your homepage if it was altered:
- Open IE and click on the Gear icon.
- Select Internet Options.
- In the General tab, delete the Home page address and replace it by your preferred one (for example, Google.com).
- Click Apply and then select OK.
Delete temporary files:
- Press on the Gear icon and select Internet Options.
- Under Browsing history, click Delete...
- Select relevant fields and press Delete.
Reset Internet Explorer:
- Click on Gear icon > Internet options and select Advanced tab.
- Select Reset.
- In the new window, check Delete personal settings and select Reset.
Do not let government spy on you
The government has many issues in regards to tracking users' data and spying on citizens, so you should take this into consideration and learn more about shady information gathering practices.
Avoid any unwanted government tracking or spying by going totally anonymous on the internet.
You can choose a different location when you go online and access any material you want without particular content restrictions. You can easily enjoy internet connection without any risks of being hacked by using VPN.
Control the information that can be accessed by government any other unwanted party and surf online without being spied on. Even if you are not involved in illegal activities or trust your selection of services, platforms, be suspicious for your own security and take precautionary measures by using the VPN service.
Backup files for the later use, in case of the malware attack
Computer users can suffer from data losses due to cyber infections or their own faulty doings.
Ransomware can encrypt and hold files hostage, while unforeseen power cuts might cause a loss of important documents. If you have proper up-to-date backups, you can easily recover after such an incident and get back to work. It is also equally important to update backups on a regular basis so that the newest information remains intact - you can set this process to be performed automatically.
When you have the previous version of every important document or project you can avoid frustration and breakdowns. It comes in handy when malware strikes out of nowhere. Use for the data restoration process.
From our report of Jul 2017 · not reviewed since
Eliminate "System Alert! Add Extension" threat
Add Extension" removal.
However, if you have plenty of time or do not want to use additional software, you can opt for the manual elimination method. Thus, you need to investigate the system, look up for unknown programs and browser extensions that may have been recently installed.
Add Extension" manually. Though, you have to be careful and follow each of the steps carefully.
Questions about System Alert! Add Extension" pop ads
Can I safely uninstall System Alert! Add Extension" pop?
If you did not install System Alert! Add Extension" pop yourself and it is not part of your hardware or a program you rely on, yes. Uninstalling an unwanted program does not harm Windows.
Before you do, search the exact name and publisher to be sure it is not a driver tool, a printer utility or a game launcher with an odd name. Then remove it from Settings, Apps, Installed apps.
Ignore any offers or warnings in its uninstaller about losing protection or performance. Afterwards check Startup apps and your browsers for leftovers, and restart once to confirm that it does not reinstall itself.
How do I stop programs like System Alert! Add Extension" pop from being installed again?
Most unwanted programs arrive through installers, so the fix is in how you install software. Download programs from their official sites or the Microsoft Store, not from download portals or ads above search results.
During setup, choose Custom or Advanced installation and untick every extra offer, including browsers, toolbars and optimizers. Decline update prompts that appear inside other programs unless you know them.
In Windows Security, turn on reputation-based protection and potentially unwanted app blocking. These steps would most likely have stopped System Alert! Add Extension" pop before it reached the app list.
My scan found nothing, but the ads continue. Why?
Because the source may not be a file a scanner looks for. Browser notifications are a permission stored in the browser, and many adware extensions are not flagged because they come from an official store.
Some ad-supported programs are only reported if you enable detection of potentially unwanted apps. So a clean scan does not mean the job is done. Check each browser's notification permissions and extension list by hand, and turn on Potentially unwanted app blocking in Windows Security before scanning again.
Why is my browser so slow since the ads started?
Each page now does extra work. An adware extension reads the page, decides where to put ads, loads them from ad servers and reports your visit, and that happens on every tab. Ad-supported programs add their own background activity.
Removing the extension or program usually makes the browser fast again at once. If it stays slow, open the browser's own task manager with Shift+Esc in Chrome or Edge and look for extensions using a lot of memory or processor time.
Did System Alert! Add Extension" pop collect my data?
Adware typically collects what it needs to choose ads:
- the sites you visit
- search terms
- approximate location
- browser and system details
Extensions with permission to read and change data on all websites can technically see everything on those pages, including forms. That is a privacy problem rather than proof of theft.
If you typed card details or passwords while it was active, changing the most important passwords is a reasonable precaution. Clearing cookies after removal ends the tracking sessions it may have started.
I let a "support technician" from an ad connect to my PC. What should I do?
Act quickly but calmly. Disconnect the PC from the internet first, so the connection ends. Uninstall the remote access tool they asked you to install and check Installed apps for anything else added during the call.
Run a Microsoft Defender full scan and offline scan. From another device, change your e-mail and banking passwords and sign out of all sessions.
If you paid by card, bank transfer or gift card, contact your bank or the card issuer immediately, and report the scam to the police. Do not answer if they call back.
Can an adware pop-up infect my PC just by appearing?
No. A pop-up, a notification or a new tab is only a web page or a message. It cannot run programs on Windows by itself, provided the browser and Windows are up to date. Infection needs a step from you:
- running a downloaded file
- installing an extension
- giving a stranger remote access
That is why scam pages work so hard to make you click. Close such pages with the tab's X or by closing the browser, not with buttons inside the page, which may start a download.
Do I need to reset my browser after removing System Alert! Add Extension pop?
A reset is a good last step, because it undoes settings that the program changed. A reset restores the home page, new tab page and default search engine, and turns off extensions.
It does not delete your bookmarks or saved passwords in the main browsers. Add back only the extensions you trust, one at a time.
Will Fortect remove System Alert! Add Extension" pop?
Fortect scans Windows for malware and unwanted programs and repairs the system files and settings they change, and its free scan shows what it finds on your PC before you decide anything. For System Alert!
Add Extension" pop, follow the plan above as well: the browser steps take back permissions and settings that no scanner treats as a threat, and uninstalling the program that brought it removes the source.
Run Microsoft Defender's full scan and, if anything was found, its offline scan as a second opinion. If the symptoms are gone after the plan and both scans are clean, there is nothing more to do.
Sources
- Google Chrome Help: Use notifications to get alerts (no longer online) (read October 7, 2026)
- FTC: How to recognize, remove and avoid malware (read October 7, 2026)
- Microsoft Learn: Microsoft Defender Offline (read October 7, 2026)
- Microsoft Learn: How Microsoft names malware (read October 7, 2026)