I have even followed everything that Tech support advised on the phone.
I was able to reinstall 32bit version but the 64bit version keeps saying that it is already installed. And that is after removing everything for Sony being romoved and even in the registry.
Jeff,
I had a problem some while back when Vegas wouldn't start. Can't remember whether it was v8 or v9, but here's what helped.
There's a program in the Vegas Pro install directory called PRSConfig.exe. It's to do with the Problem Reporting Service.
Go to that directory and start up that program to see what defaults are set. If set to 'Full', choose one of the others to see if that makes any difference. It did for me.
I don't think it only effects how and what is reported on errors but how strict error handling is.
A VMS 10 user ran into a similar issue, seems to be a .NET problem. He solved it by copying over missing files from another similarly configured machine. Perhaps Microsoft has a .NET repair installer you can download?