Windows crashing (DIRECT RT 2008)

We use both Media Lab and Direct RT for our research and we have been experiencing some problems I am hoping you can help us with (I have posted this problem under both program's troubleshooting forums).

We have both programs set up in a lab setting (on a network but we have our own log-in for research). We are running the 2008 version of both programs and its on windows 7. Both programs have been locking-up and freezing on us and we are not sure why. It doesn't happen at the same point in the study each time either, it is rather random actually.

It is really hindering our study and research though because once participants have started we cannot restart them, so once it freezes up we have lost that participant and cannot reuse them.