This also happened to me. Hopefully you are attempting to run LabView on a dedicated computer. Ours had "issues" with some of the other software we were running. Here's what we did: We re-imaged the computer (backed up everything and re-loaded the OS). Computer has been up and running excellent ever since. There was a lot of useless software originally on it, we took it all off. If you are able, only run what you need on it. Also, we have found that LabVIEW 6 runs strangely on computers with less than 128 MB of RAM. Our project computer currently has 320 MB of RAM (and 40 GB HD) and it runs perfectly.
Hope this helps. If you have a specific error code, let me know. Otherwise, from what you have posted, I believe this is the answer.