When I bootup my computer I get the following error: Bad or Missing C:\DOS\Hymem.sys. Error Config.sys line 2 HMA not available: Loading DOS Low. After it goes past that screen Dos seems to load and work OK. What does this error mean and what can I do to fix it.

Sure you've even got enough memory to use it? Sounds like the machine might have been "robbed" of anything above the base 640K while sitting around for a while (or possibly bad RAM). Otherwise, it may be as it states "bad or missing C:\DOS\Himem.sys". First see if it's in the DOS directory, then if it is, it's probably corrupted. Reinstall the file from whichever version of DOS (5.0-6.22) it came from...

... is this a recent error? You could try and edit the "config.sys" file were it says: DEVICE=Hymem.sys change it to : REM DEVICE=Hymem.sys See if that will help? REM= remark

LOL You won't make it work by REMming it out. Firstb see if it's missing. If it's there it may be corrupt or it may be the wrong version. Usually theb version is indicated by the time stamp. For DOS 5 it's: 11-11-1991 05:00 11,616 HIMEM.SYS and so on ===================================== If at first you don't succeed, you're about average. M2

"...seems to load and work OK...." ... maybe NOT needed !

If it doesn't load HIMEM.sys he doesn't have access to any memory areas above the bog standard 640K, DOS can't be loaded into upper memory to save some precious lower memory. An Expanded memory manager can't be loaded either such as EMM386.exe allowing access to any more ram their system has (if any more ram above 1 meg that is).

Gentlemen, don't omit mentioning to run the 'load dos high' command which accompanies himem.sys. Himem is only the driver, it needs the command load dos high to actually kick (it) in gear.