I to have been having trouble using Streetsmart in Windows 7. Their tech support is no help. .net framework is 3.5.1. Haven't figured out why this works, but discovered that if I set up a new standard user (i.e. not administrator) account and log onto that, Streetsmart works. If you mess around with that account too much Streetsmart quits working and hangs at various atartup stages. For example I created a standard account, got Streetsmart to work, then changed it to an administrator account. It quit working, and continued to hang even when I changed the account back to standard. So I have a special account now that I do nothing with except run Streetsmart. Have to switch users to get to it, but it's better than nothing.