I was attempting to upgrade a vCenter from 5.5u2D to 5.5u3. We noticed that the installer would take a long time in the phase “Extracting Registration Tool”, and when I mean long I’m talking anywhere from 10-30 minutes. By going to %TEMP% and then viewing the vminst.log, I could see that the last thing done was an unzip of sorts in C:\windows\temp. When I tried to view that directory via Explorer, it was really slow and would only show a subset of files at a time. The problem was that there thousands (at least) of these KRB5_RC files litering the directory. This was making all kinds of operations in that directory painfully slow.
In order to resolve it, I set the environment variable per the KB and rebooted. After rebooting I deleted all of the KRB5 files by using the following BAT file:
By deleting subsets of the files, the “*” wildcard operator is not overwhelmed by the number of files that it has to enumerate.
My upgrade failed because it dragged too long due to this issue, hopefully you can check out your vCenter for this issue and clean up the files prior to getting into your change window!