VB application on Win 2000

Does anybody know what's going on here:
Database application uses Access DB located on PC with Win 2000. It was written several years ago and everything was fine until client machines which run exe were upgraded to Win 2000 Pro. Although client PC are very similar to each other (750 - 933 Pentium III processors and 128 MB RAM), some of them work fine as they did when they had Win 98, but some of them stopped to work properly - When user wants to open Account screen having Order Book screen, it appears for very short time and then is's replaced back with Order Book screen. Then used memory grows, processor is 100% in use and after several seconds "Out of memory" message appears. Where do I have to look for a problem?
Thank you.
Vlad

Sounds like a nasty loop, Like populating a data-grid or textbox. This happens if you create a infinite loop. I would check your For-next and do-while loops in a trace when the user attempts to open a accounts screen.

Jean-Guy

Thank you for a quick response. What do you think about why it happens only on 3 from 15 machines (all of them now Win 2000) and only after upgrade to Win 2000?
Vlad

If the program is using API calls that may have changed Check any dll calls you may make, Also dll's like msvcrt.dll etc can be diffrent depending on what apps are installed and what service packs are on the machines. It sounds like a API could be returning a invalid number that your are looping off of. The only thing to do is run the code on the bad machines with logging to a file to trace the code (or install VB and trace the form load)

Jean-Guy

I think all APIs were the same on 2 machines I tested. I created Ghost (disk cloning program) image from the partition of 'good' machine and restored that image on the 'bad' machine. After rebouting I've got 2 machines with the same sets of software including Windows with all its APIs. 'Bad' machine still was not working. I checked all event procedures, like Load, Activate, QueryUnload, Unload in both forms and did not find any For/Next or Do loops.
The idea to install VB and all stuff on 'bad' computer is pretty difficult to be realised. Also such kind of problems do not appear in development environment very often. So, if I wont find anything else, I'll try it.
Thank you.
Vlad