SYS File Extension

SYS file icon
Windows System Format
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What is SYS file?

The SYS extension indicates system files used in Windows and MS-DOS operating systems. Such files include data regarding changeable drivers, devices’ settings and other functions. Without SYS files, operating of a system would be impossible because they enable communication between Windows system, devices and external devices.

Typical SYS files

The most common type of SYS files is CONFIG.SYS. It well known because it contains all information and configurations of driver’s performance necessary to run MS-DOS. Other SYS files are:

  • MSDOS.SYS – Contains basic code of DOS system, called the DOS kernel.
  • IO.SYS – contains standard DOS drivers and a program responsible for start of DOS. It is used in DOS and Windows 9x.
  • KEYBOARD.SYS – contains information about keyboard layout.

Location of SYS files

A large part of SYS files within system is hidden. Usually they can be found in main Windows folder, and in Vista version and newer, SYS files are usually found in Windows system32 drivers and Windows WinSxS.

Additional information

  1. SYS files can be used in Mac environment provided Windows system is installed.
  2. SYS files are stored as text files in binary format.
  3. SYS files are sensitive to any virus infections and malicious software effects.

Programs that support SYS file

We hope we helped you solve the problem with the SYS file. If you do not know where you can download the application from our list, click on the link (which is the name of the program) - you will find more information there on the location where to download the secure setup version of the required application.

What else may cause problems?

There can be more reasons which determine that you are not able to open the SYS file (apart from the lack of the proper application installed).

First - the SYS file may be incorrectly associated with the application installed to support it. In this case, you need to change this association by yourself. To do this, right-click on the SYS file that you want to edit, click "Open with" and then select the program from the list that you have installed. After this operation, the problems with opening the SYS file should be solved.

Second - the file you want to open can simply be damaged. Then, the best solution is to find a new version of given file, or download it again from the same source as before (maybe for some reason in the previous session the download of the SYS file has not been completed and it cannot be opened properly).

Do you want to help?

If you have additional information about the SYS file, we will be grateful if you share it with our users. To do this, use the form here and send us your information on SYS file.

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