I don’t get a completely clear description from your comments. Nothing wrong with the comments but it doesn’t set up the issue well for me. I'm not clear on the specific nature of the failure. It sounds as if it is the ability to do modeling is okay but it is not scaling properly?

On the guess that the problem is due to the video adapter card:

Computer b is having the problem. If I understand, you have relocated the Zscreen from computer B to computer A and it works okay. Is that correct?

If so, next would be to swap the video adapter card from computer B to computer A to see if computer A still works okay when modeling. You’ll want to have the install software for this adapter card on hand before running the experiment. Shut down computer A, remove or disable the video card from Computer A and put in the video card from computer B.

This may or may not work as not all video cards are compatible with all computers. If there is any doubt about compatibility, call Dell support and ask.

Also are you certain that the Nvidia FX 3400 is 1) able to do 3d modeling and 2) *expressly stated* as compatible with the other components?

**Edit: Sometimes there are general compatibilities for video such as "Open-GL" while other times the adapter has to provide express driver support for the specific hardware it is intended to work with