I was trying to move the AppData folder (or at least Roaming) off of my SSD so I could make a symbolic link, but I couldn't move everything due to some of the files being in use. After a restart, I have missing icons, missing desktop background, and missing settings in some programs (e.g. saved passwords in Chrome). I keep trying to move everything back, but when I restart, those moved files have been deleted.
I tried a system restore point from before the experiment, but it did not help.
I also tried changing the location of AppData/Roaming in it's Properties dialog, but the location was changed back to C drive and the Location tab was removed from its Properties even before I restarted...