HIMEM.SYS
| Component of Microsoft Windows | |
 | |
| Other name(s) | HIMEM (often simply referred as such) |
|---|---|
| Type | Device driver |
| Introduced in | Windows 3.0 MS-DOS 5 IBM DOS 5 |
| Included in | MS-DOS IBM PC-DOS Windows 3.0 Windows 3.1x Windows 9x |
| Last included in | Windows Me |
HIMEM.SYS (often simply referred to as HIMEM) is a device driver file for MS-DOS and other DOS systems that enables them to use more than the conventional 640 KB of RAM. This area of memory access is also commonly referred to as the "High Memory Area" (HMA). It is required by Windows/386 2.xx and Windows 3.x to run in 386 Enhanced Mode.