You're right, it will be almost impossible to get at the root cause at this point, but there's still a couple of follow-up questions I can ask that might narrow things down a bit:
1. When your computer locked up completely, were you doing something in CVI, or in a CVI program, and if so, do you remember what it was?
2. Did you try restarting CVI more than once, always with the same result?
The fact that an installation repair fixed the problem suggests that there was some missing file or registry key. Given that things seem to be working now, we won't be able to find out what exactly was missing. But if the same thing were to happen again, there is something you can do that might give us some more information:
1. Run this utility: C:\Program Files\National Instruments\CVI90\bin\ConfigCVILogging.exe.
2. Under "Logged message types", select "Info".
3. Under "Log output to" select "File" and specify some path of your choice.
Then, when you run CVI, it should create a log file with some trace-type information. If CVI runs into any problem at startup, the contents of the log might be helpful to us in order to diagnose the problem.
Luis
