I was going to write about this actually.. yet I found that askburton has already a great item for it.. so if you get this error.. here is a help link ... http://blogs.msdn.com/askburton/archive/2005/01/27/362083.aspx let me know if this was helpful....

Repair and Reinstall (ie. uninstall and then reinstall again) are not supported on the comming Beta2 of Visual Studio Team Foundation. If you want to reinstall or repair your application and keep your existing data, you will need to backup the data first...

I would love to hear from you on how was your experience installing Visual Studio Team Foundation (both Applcation Tier and Data Tier). It is our goal to provide you with the best setup experience. Any exprience you would like to share? Anything you would...