OK, I don't know why Atlassian calls 1.8 an upgrade. This is at best, a terrible beta test. Are there any problems with reinstalling 1.7 on Windows?

[Nukezm]

Will reinstalling 1.7 cause any problems if I upgraded  to 1.8?

[njuice]

If you get any errors, try also deleting the C:\Users\[username]\AppData\Local\Atlassian folder. This will destroy all your settings, of course

[Seth]

If you uninstall 1.8 first, should be no problems. I've done it myself and haven't noticed anything.

Uninstalling SourceTree does not delete your repositories, and (for me) did not even delete the bookmarks for my repositories.