Cannot Use /U Switch with DOS=LOW and MOUSE.COM Version 8.0 (75081)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 5.0a
    Microsoft MS-DOS operating system 6.0
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q75081


Microsoft Mouse drivers versions 8.0 and later allow for the use of an XMS driver to load themselves high. The /U switch allows you to load the mouse driver high, but does not work if MS-DOS is loaded into conventional memory. MS-DOS loads into conventional memory with the line DOS=LOW in the CONFIG.SYS file, or the lack of a DOS= line in the CONFIG.SYS file.

To work around this feature, type the following command:

setver 4.00

Make sure that SETVER.EXE is being loaded in the CONFIG.SYS file, and then restart the machine. To verify that the mouse driver is loading into XMS, type MEM /C. The size of the driver in conventional memory should be approximately 3.5K.

NOTE: Microsoft does not recommend using the /U switch when DOS=HIGH with Microsoft Mouse Driver, version 8.0. For more information, query on the following words:

conflicts and and DOS=HIGH


MOUSE.COM uses an XMS Sub-Allocate call to load itself high. This call requires MS-DOS to be loaded into the HMA before the mouse can load high.

MOUSE.COM has a version check built into it that allows it to load into the HMA in MS-DOS versions earlier than 5.0. If the MS-DOS version is earlier than 5.0, MOUSE.COM does not check to see if MS-DOS has been loaded high first. Loading SETVER.EXE allows MOUSE.COM to make the appropriate XMS initialization calls to allow for proper HMA loading.

Modification Type: Major Last Reviewed: 5/12/2003
Keywords: KB75081