System Files Reference Book

File – a storage unit filled with data, information, settings, or commands about a program

The computer system consists of various files that use a different amount of its resources. Each PC system is filled with thousands of filenames located in different locations.

You can identify these files by looking at their extensions (short additions that are added to the end of their name). No matter which OS is installed on your computer, files are organized with the help of folders. They are stored on a hard drive and other storage devices. You can change or rename most of your files.

The most popular types of files are:

• system files
• program files
• data files
• executable files
• text files 
• directory files.

Dangerous files pose a serious risk to the system

There are two groups of files – harmless and malicious. Harmless files are totally reliable system components that are needed for a proper PC’s functionality. They are related to legitimate applications, so you shouldn't remove them from your computer. The most important ones are system files. They are critically related to the normal function of a computer. After deleting or modifying such files, you can seriously injure it.

In the meanwhile, malicious files can pose serious harm to your computer. They can significantly decrease the system’s speed, stability, and functionality because they tend to consume lots of memory and disk space. Beware that it’s very hard to spot the malicious file without the help of security software because malware creators use various tricks for hiding them in the system.

Main signs showing that the file is malicious

While it is not recommended checking the trustworthiness of the file manually as, in most cases, they use filenames which are almost identical to the ones that are used by legitimate applications, there are several signs that should make you worry and initiate a full system scan with some anti-virus tool. 

At first, the name of such a file may seem very similar to the name of a legitimate file. However, after looking at it closer, it becomes clear that it is written with some spelling mistakes.

Additionally, check the file's location. If the supposed System file is located in C:\\Program Files, there is a high possibility that the component is malicious. The easiest way to know whether your PC system is filled with malicious files or not is to scan it with the reliable anti-spyware.

For helping you to see the difference between malicious and legitimate files, we created the Files section. Here, you can find hundreds of different files that are related to either legitimate applications or computer viruses. They all can be identified by their extensions. The most popular of them are .exe, .dll, .db and .lnk. Of course, these are more malicious files than legitimate files in this section because our aim is to help you identify an infected PC system.

Each file's description includes a list of tools that are recommended for a computer’s diagnosis. If you see that you are dealing with the malicious file, you should select one of our recommended programs and remove it from your computer.