[Ham-Computers] Problem with NTVDM.exe

[WA5CAB at cs.com]

OS is W2K.  I run an early 90's vintage (and heavily modified by me for 
dealing with radios, radio parts and manuals) accounting package that currently 
runs under dBase 5 (AKA dBase for DOS).  When I start it, with a shortcut, 
NTVDM.EXE starts and runs the CPU untilization up to about 26% average.  The 
application has worked fine for years up through about 13:00 yesterday when 
I shut it down (but not the computer) and left to haul a load of shipping 
to the Post Office.  When I got home, I started the accounting system to 
enter the postage for some international items we had just shipped and some 
other tasks.

The package came up normally (and still does) but after only a few steps 
headed toward entering an invoice in A/P it locked up.  I started Task Manager 
and shut down the dBase application and tried again.  Same results.  The 
odd thing is that the cursor at the location I'm trying to enter a keystroke 
continues to blink.  Some time last night, I noticed that at the point where 
it locks up, the server utilization figure for NTVDM goes to zero.  And 
later I noticed that while running it, just about any time the utilization goes 
to 35% or so it locks up.  But I just opened a huge manual with my TIF 
viewer and another PDF one with Acrobat and by paging forward as fast as it would 
go was able to run the CPU utilization above 40% consistently with nothing 
locking up.  Of course neither the TIF nor the PDF viewers run under NTVDM 
but that makes me doubt the CPU is the culprit.

I did some web searching and found several hits about fixing problems with 
NTVDM.EXE, most being registry fixers.  I downloaded one of those and ran 
it.  It found a bunch of errors in the registry but fixing them didn't fix the 
accounting system problem.

I found that my wife's machine, running supposedly the same OS had a copy 
of NTVDM.EXE and another file obviously related that were about 6 months 
newer.  I tried to copy those over the earlier version but discovered that every 
time I did, more quickly than I could navigate back to looking at the 
SYSTEM32 folder on this machine, something had replaced the files I had just 
copied with the original versions.

I have MacAfee on this machine and own a copy of PC Tools SpyWare Doctor 
that for various reasons I don't keep loaded all the time.  I loaded SWD and 
did a scan but it didn't find anything.  I downloaded one of the registry 
cleaners (RegCure) and ran it.  I also ran Registry Mechanic which I've owned 
for a while.  RegCure found a bunch of problems which I let it fix.  But that 
didn't help the accounting system problem.

Anyone have any ideas?

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480