Error 7 (Windows error 999)

I've been getting this error over and over again and iTunes won't open. I followed all the instructions in this thread (https://discussions.apple.com/thread/2632908?start=0&tstart=0), and have uninstalled and reinstalled all the Apple programs according to these instructions (http://support.apple.com/kb/HT1923) and have repaired NET Framework according to these (http://support.apple.com/kb/TS3074) multiple times to no avail. Any ideas for what else I can do?