I installed quicktime on windows 7 and windows installer has been throwing errors since then: when I launch a windows installer based setup I get a Windows Installer has stopped working error. I ran SFC, I used system restore, I sent dozens of reports but the error won't go away. I believe the issue is caused by the application compatibility database that got corrupt because once I got an error about the application compatibility tool at the same time of one of the windows installer crashes. What can I do other than painfully reinstalling windows 7?