Home : File Types : SYS File (2 File Associations)

.SYS File Extension

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File Type 1Windows System File

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CategorySystem Files
FormatText and Binary

Text and Binary

This file is saved in a plain text format or a binary format. If in a plain text format, it can be viewed with a text editor.

What is an SYS 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. The file is commonly used to store device drivers and other core Windows functions.

More Information

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.

How do I open a SYS file?
Microsoft Windows LogoWindows
Microsoft Windows
Mac OS X LogoMac
Parallels Desktop for Mac with Windows installed
Updated 4/15/2016

File Type 2Motorola Driver File

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Rare Uncommon Average Common Very Common
CategorySystem Files


File format categories include Binary, Text, XML, and Zip. The format of this file type has not been determined.


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.

More Information

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.

Program(s) that open SYS files
Microsoft Windows LogoWindows
Used by the operating system
Updated 4/6/2007