This is several days old and maybe you've found the solution to your problem already, but...
Be sure when reinstalling the OS that you immediately run Windows Update to ensure that all the updates are installed. You may have to run Windows Update several times to get everything (and there will be numerous reboots during the process). I had a similar problem with another application (not even Microsoft), and discovered after much head banging that I was missing a patch.
Another thing you migh look into is a bad spot on the hard drive that's causing a read error? Try uninstalling Streets, defragmenting your hard drive (that also checks for disk errors, if I remember correctly), and then reinstalling Streets.
Hope that helps...
Regards, Chris