Map2000 on XP: Fatal Memory Error

Hello,
We have three Acad Map 2000 installations on XP Pro. (Yes, I know, not
supported by Autodesk).
Up until recently, all three have worked well. However, one of the
machines (a fairly new Dell) had a hard drive failure. Drive has been
replaced and all has been reloaded.
However, it sometimes comes up with the following errors --
particularly when opening a large map:
(AutoCad Error Aborting) Fatal Error: Unhandled Access Violation Reading
0X0001 Exception at 659acceeh Then, after clicking OK the next error
message is: AutoCad Map 2000, acad.exe-Application Error) The instruction at
“0x73ddl35l” referenced memory at “0x00000004”. The memory could not be
“read”.
It sort of looks like a memory chip issue, but since other
activities on this machine do not have a problem, I wonder if there is a
"large file" or other driver that may not have been loaded in properly.
Any thoughts would be appreciated.
Rich