They and others can be found at http://www.systeminternals.com/
I had a case today with a PC that I run a lot of automated scripts on every night.
I tried to manually start AutoCAD 2006 and noticed that it took an extremely long time to start. I actually thought AutoCAD had locked up. Of course I could reinstall or repair AutoCAD but I wanted to find the reason for this so I fired up Filemon, filtered on *acad* but I didn't notice anything strange. I then run Regmon and found that it was a lot of traffic to some keys in the registry.
I took a look at the keys in question and found the cause. It was related to one of the new features in AutoCAD 2006, the Drawing Recovery Manager.
The locations where:
If where thousands of entries in there pointing to files. Not sure exactly how so many could get in there but since I don't is in need to use drawing recovery manager on that PC I deleted these registry keys and when starting AutoCAD again it was as quick as it should.
It seems like AutoCAD has a hard time to start when there are so many files listed. Not really a bug but something that the developers at Autodesk might take a look at. Especially the reason why AutoCAD thinks that it might need to recover drawings when AutoCAD haven't crashed. I any several users have seen this behavior before. And that looks like a defect to me.
To prevent this from happen again I first though about deleting these registry keys automatically but remembered that there was a new system variable to control this. RECOVERYMODE
Controls whether drawing recovery information is recorded after a system failure.
0 - Recovery information is not recorded, the Drawing Recovery window does not display automatically after a system failure, and any recovery information in the system registry is removed
1 - Recovery information is recorded, but the Drawing Recovery window does not display automatically after a system failure
2 - Recovery information is recorded, and the Drawing Recovery window displays automatically in the next session after a system failure
So I ended up setting it it 0.