Hi everyone, I don't know if I've posted this in the right area. We buy old 486's and 386's with our own funds to be used by disabled people. We bought an old pc recently. when we got it - it was working win 3.1. My colleague mucked around with the cmos settings and we cannot get it back to the way it was. It says "memory mismatch". The only info I can give you is that when the pc starts up it says "D.M. Peripherals - DataTech Enterprises - DTK 386" I have been on the net for about 3 hours but can't find any help. Can anyone please, please advise me. Many thanks - jules

Usu this is caused by changing the amount of memory installed in the machine. Can also be caused by changing certain memory options or by a failing CMOS battery - or even a corrupt CMOS chip or memory. Does it report the correct amount (more or less) of memory? Have you tried saving the settings and restarting? Can you boot to a DOS prompt at all? Also - make sure any memory chips are snug in their sockets - can't hurt. Hope this isn't too basic, not sure how experienced you are with changing the CMOS.

Thanks jboy - I'm not experienced very much at all with changing the CMOS. No I cannot get it to boot to a dos prompt at all. It either says "memory mismatch" or "hard disk not present or not configured". At the risk of sounding stupid, we are not sure exactly what the correct memory is (or was!) Any further advice you can give would be greatly appreciated. Cheers!

I agree with jboy. Try this: At power/start up hit the delete key to get to CMOS. scroll down to the Hard disk autodetect option. Check to make sure the system even detects the drive. If so select Y .Then, write to CMOS and exit. If that don't work try this: As above goto CMOS and select the Advanced CMOS Configuration Settings(the option name may be different but similar) Look for the "old settings"or "previous config settings" and try to restore the old config. Depending what and how much was done, this might undo the problem. Good Luck

Ok, as suggested above, try to get to the setup screen - usu by hitting del, altho' it might be one of literally dozens of other key combos - often instructions will appear on the screen. Older machines did not always have the 'autodetect hard drive' feature' - but one thing at a time. If you can get to the set up, the memory should be listed - this IS autodetected. Of course, if it is a bad battery or a bad CMOS chip, this either won't work, or it won't work for very long. The ROM BIOS manufacturer's name should appear on the screen - post back as to the name - this could help identify the correct key combo to access the setup screen - if you're still having difficulties.

Thanks everyone very much. I'll give it a go!