The File Extensions Database

.SYS File Extension

  • Developer by: Microsoft
  • Category: System Files
  • Format: Text and Binary

What is an .SYS file?

.SYS is Windows System File

A SYS file is a system file used by Microsoft DOS and Windows operating systems. It contains system settings and variables, as well as functions that are used to run the operating system. SYS files are commonly used to store device drivers and other core Windows functions.

Some examples of SYS files include the following:

  • IO.SYS: stores the default DOS device drivers and the DOS initialization program; used by DOS and Windows 9x.
  • MSDOS.SYS: contains the core operating system code for DOS, known as the DOS kernel.
  • CONFIG.SYS: contains the primary configuration information used by DOS.
System files are most commonly found within the Windows directory of a Windows installation. In particular, many SYS files are stored in the Windows\winsxs directory in later versions of Windows.

Programs that open Windows System File
Microsoft Windows
Parallels Desktop for Mac with Windows installed
File Type 2 Motorola Driver File
Developer by: Motorola Category: System Files

Device driver used by Motorola cell phones; allows the phone to communicate with computer and transfer files to and from the device; typically installed with the software installation CD included with the cell phone.

Example Motorola driver files include the "m56pci.sys" device controller and the "p2k.sys" file, which enables the P2Kman program to upload and download files from Motorola Vxxx cell phones.

How to solve problems with SYS files

  • Associate the SYS file extension with the correct application. On :
    Windows: Right click on any SYS file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.SYS files". Mac: Right click (or Ctrl-click) the SYS file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .SYS is Windows System File. Because only the current version supports the latest SYS file format. Search, therefore, e.g. on the Microsoft manufacturer website after an available .SYS is Windows System File update.
  • To make sure that your SYS file is not corrupted or virus-infected, get the file again and scan it with antivirus software.