Ads by DNSBlock: what it is and how to remove it
If you have been convinced to install DNSBlock adware, you should have already noticed that this program functions quite suspiciously. Although it is advertised as a convenient tool that can keep malicious Internet sites out of user's reach, its seems that this application can redirect the user to such sites itself.
Facts checked October 6, 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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Ads by DNSBlock: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Distribution | Not recorded in the old report |
| Damage | Not recorded in the old report |
| Name | Ads by DNSBlock |
| Type | Ad-supported program |
| 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 | One write-up by a security site; details still limited |
|---|---|
| Program | Ads by DNSBlock |
| First seen | 21 July 2016 |
| Facts checked | 6 October 2026 |
How to remove Ads by DNSBlock
Uninstall first, then remove what stays behind, so the ads do not come back after a restart.
Step 1: Uninstall Ads by DNSBlock
Ads by DNSBlock is removed like any other program, from the list of installed apps. In Windows 11 that is Settings > Apps > Installed apps, in Windows 10 Settings > Apps > Apps & features, and in both you can also use Control Panel > Programs and Features.
Select Ads by DNSBlock, click Uninstall and follow the uninstaller to the end. Then look at the entries just above and below it when the list is sorted by date: bundled programs install at the same minute.
Full procedure with screenshots: Uninstall a program or app in Windows On uGetFix
Step 2: Remove it from startup
Press Ctrl + Shift + Esc to open Task Manager and select Startup apps (Windows 11) or the Startup tab (Windows 10). Disable entries you do not recognise, especially ones with no publisher or with a name that copies a Windows component.
Right-click an entry and choose Open file location to see where it runs from: programs in
%AppData%or%Temp%deserve a closer look. Some entries are not listed there but in the registry Run keys, which the procedure below shows how to check.Full procedure with screenshots: Stop apps from opening at startup On uGetFix
Step 3: Delete the folders left behind
Uninstalling often leaves the program's folders, and some threats reinstall themselves from them.
Press Windows + R, type
%LocalAppData%and press Enter, then do the same for%AppData%and %ProgramData%, and look for folders named after Ads by DNSBlock, its publisher or created on the day the problem started.Delete those folders, and check
C:\Program FilesandC:\Program Files (x86)too.If Windows says a file is in use, end it in Task Manager or delete the folder after a restart in Safe Mode. The folders are the same in Windows 11 and Windows 10.
Full procedure with screenshots: Remove what malware leaves behind in Windows
Step 4: Reset the browser
A reset removes what the steps above could miss:
- changed start pages
- site permissions
- hidden settings
In Chrome open Settings > Reset settings > Restore settings to their original defaults; in Edge Settings > Reset settings; in Firefox Help > More troubleshooting information > Refresh Firefox.
Tip: Bookmarks and saved passwords stay, while extensions are turned off and the search engine and start page return to the defaults.
Reset every browser on the PC, including Edge, which Windows 11 and Windows 10 always have.

Chrome on Windows 11: Settings > Reset settings. Full procedure with screenshots: Reset a browser and fix a hijacked search engine
Step 5: Scan the PC, then run the offline scan
A scan finds the parts of Ads by DNSBlock that the manual steps cannot see. In Windows Security > Virus & threat protection > Scan options, start a Full scan and quarantine what it reports.
Follow it with Microsoft Defender Antivirus (offline scan) > Scan now, which restarts the PC and checks the disk while Windows and the malware are not running.
It takes about 15 minutes and works the same in Windows 11 and Windows 10. If either scan finds something, run the full scan again after removal until it comes back clean.

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
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
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.
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 2016 · not reviewed since
Should you remove DNSBlock virus?
If you have been convinced to install DNSBlock adware, you should have already noticed that this program functions quite suspiciously.
Although it is advertised as a convenient tool that can keep malicious Internet sites out of user's reach, its seems that this application can redirect the user to such sites itself. Just like any other typical ad-supported program, this one also advertises numerous third-party websites by displaying their ads on user's screen at random times.
When this program is active, it connects to its server via user's network connection and loads various advertisements, and then displays them in a form or pop-up ads (most frequently) and also banners or in-text links. Ads by DNSBlock typically seem trustworthy and catchy at the first sight, however, trusting them may be a bad idea because you can never know where these ads can take you.
Be aware of the fact that they can force you to visit highly dangerous sites that promote possibly infectious content, such as fake Java or Flash updates. If DNSBlock ads started to appear on your screen, stay alert and try not to click on them until you remove DNSBlock from your computer. You can easily delete it with or another reputable anti-spyware software.
Users who have their computers hijacked by this program says that it works suspiciously, but what annoys them the most is that this program slows down computer's performance. That can be explained easily. To load up its ads, this application communicates with its remote server, so it uses computer's active network connection for that.
It also exploits computer's resources to run its processes; meanwhile, other programs need them as well. As a result, all these activities slow overall computer's performance. That is yet another reason to remove this ad-supported application from your computer. However, that is not the last negative thing that we have to say about this dubious application.
We have already received several reports from the users claiming that they have noticed the presence of DNSBlock on their PCs even if they haven't downloaded it by themselves. That's because it is usually distributed bundled with other free programs. To learn more about this distribution method, read the information provided in the next paragraph.

From our report of Jul 2016 · not reviewed since
How did DNSBlock hijack my PC?
This questionable application belongs to a huge family of adware-type programs that are also known as potentially unwanted programs (PUP) due to a misleading distribution method ('bundling').
This method is a legitimate way to make people install unwanted add-ons, plug-ins, toolbars, and extensions on their PCs. In other words, right after installing a freeware, you may find DNSBlock ads within your web browser, experience redirects, and browser's slowdowns. Fortunately, it's quite easy to prevent this from happening.
If you are going to install a download manager, media player, PDF creator or another free software, you should check its Advanced or Custom settings and try to find out if it's carrying optional downloads or not. If you find suspicious apps set by default, it's a sign that you are about to install a software bundle, so make sure that you unmark all ticks before finishing the installation.
From our report of Jul 2016 · not reviewed since
How to remove DNSBlock from computer system?
In case you want to implement DNSBlock removal manually, our recommendation would be to check the system with a reliable anti-malware after in order to get rid of other PUPs that may be lurking on the system, because third-party programs that spread via bundling usually do not travel alone.
In other words, when you agreed to install the discussed PUP, you probably have allowed to install several different PUPs alongside it as well.
Questions about Ads by DNSBlock
What is Ads by DNSBlock and why is it on my PC?
Ads by DNSBlock is a program that was installed on the PC, most likely together with something else you downloaded. Free software sites and many installers add extra programs on setup pages with pre-ticked boxes, so the extra install looks like your choice even though nobody read the page.
Check the install date in Settings, Apps, Installed apps: the program you installed that day is the probable carrier. If you do not need Ads by DNSBlock, uninstall it. If it belongs to your hardware or to a program you use, search its exact name and publisher first, because drivers and their tools can have unfamiliar names.
Ads by DNSBlock will not uninstall. What can I do?
First restart the PC and try again, because the program may have been running and locked its own files. If the uninstaller is missing or fails, start Windows in Safe Mode, where most third-party programs do not start, and remove Ads by DNSBlock from Installed apps there.
If it still refuses, delete its startup entry and its scheduled task, restart, and try once more. A program that actively prevents removal is behaving like malware, so finish with a Microsoft Defender offline scan. Avoid third-party uninstallers offered on search ads; several of them are unwanted programs themselves.
Ads by DNSBlock has no uninstaller. What now?
Some adware does not register itself properly, or its uninstaller only opens a web page. First try Settings > Apps > Installed apps and the older Control Panel > Programs and Features; one may list it when the other does not.
If neither works, disable its entry in Task Manager > Startup apps, restart, and run a Microsoft Defender full scan and offline scan, which remove known adware files. Then, if anything is left, delete the folder it ran from, which you can find by right-clicking the process in Task Manager and choosing Open file location.
Can adware slow down my PC?
Yes. Adware runs in the background, loads ad scripts, opens extra tabs and contacts its servers, all of which use processor time, memory and bandwidth. Ad-heavy extensions also slow down every page, because they inspect and change it before you see it.
The effect is strongest on older PCs and when several adware programs arrived together. After removal, restart the PC and check Task Manager for anything still using a lot of resources that you do not recognise. Speed usually returns to normal once the ads stop.
I clicked on one of the ads. Am I infected?
Probably not. Clicking an ad usually only opens a page, and a page cannot install programs on an up-to-date Windows PC without your help.
You are at risk only if you then downloaded and ran a file, allowed notifications, entered card or login details, or called a phone number shown on the page. Delete any download and run a full and offline scan.
Change passwords you typed, from a clean device. Call your bank if you gave card details. If you called a number or allowed remote access, see the next question.
An ad showed a phone number and I called it. What now?
The number belongs to scammers, not to Microsoft or an antivirus company. If you only talked, hang up and do not call back. If you let them connect to the PC, disconnect it from the internet, uninstall the remote access program they used, such as AnyDesk, TeamViewer, ScreenConnect or UltraViewer, and run a full and offline scan.
If you paid or gave bank details, call your bank at once on the number printed on your card. Change any passwords you typed while they were connected, and report the call.
Does adware steal passwords?
Ordinary adware is built to show ads, not to steal logins, and most of it never touches saved passwords. The line is blurry, though. Extensions that can read every page could capture what you type, and adware ads sometimes lead to phishing pages that ask for passwords directly.
If you entered credentials on a page reached through an ad, change that password from a clean device and turn on two-step verification. Otherwise, removing ad-supported program and clearing cookies is usually enough.
Why didn't my antivirus catch Ads by DNSBlock?
Many security products do not block adware or notification sites by default, because users often agreed to them, even through a misleading prompt. Notification spam installs nothing at all, so there is no file to detect.
In Windows 11 you can make Microsoft Defender block potentially unwanted apps: open Windows Security > App & browser control > Reputation-based protection settings and turn on Potentially unwanted app blocking. If notifications caused the pop-ups, no scanner will report them; the fix is in the browser's site settings.
Will Fortect remove Ads by DNSBlock?
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 Ads by DNSBlock, 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 6, 2026)
- FTC: How to recognize, remove and avoid malware (read October 6, 2026)
- Microsoft Learn: Microsoft Defender Offline (read October 6, 2026)
- Microsoft Learn: How Microsoft names malware (read October 6, 2026)