I just discovered how to force Zune on my work pc to treat my Windows Phone 7.5 as a guest.
Unplug the internet.
If Zune can find your device in its cloud database, then it will not allow a guest mode. If it has no access to the cloud...
So why is this so important that I should start a thread not with a question but with an answer?
1) My daughter just said that iTunes was better than Zune regarding smart phones and music files.
2) It took me forever to figure this out. A post on the Zune forum said they put their pc into safe mode to finally find guest mode. Why in the name of all smartphone synchronization software suites is this not common knowledge on Zune forums?
A third reason, just to complain:
3) There is a registry hack to allow the Windows Phone to show up as a USB drive, but, unfortunately, for whatever reason, it is not functional. Would I like to use Explorer to manage content on my phone? Don't ask if you can't tell.