I'm not entirely sure how to describe this, but I booted Linux Mint, selected (I think) LinuxMint 12 from GRUB (since I haven't yet figured out how to set the selection as default and make it stick), and when the login screen came up, the background was blue and different. I restarted, ensured I selected the correct item from GRUB, but the login screen came up with the blue background again. I logged in, and found my Desktop to be completely different with no access to the software I have installed. My data appears to be intact.
I tried restarting in recovery mode but resumed normal boot, still different, still missing applications. One odd thing is that it has a big selection on the top right which when you select it, gives options for the appearance of the desktop, almost like a CSS file (Cascading Style Sheet.)
I am completely at a loss for what to do.
What did I break?
I forgot to mention that when I rebooted or initially booted, the computer restarted itself after selecting Linux Mint 12 from GRUB. It has done that every time I freshly boot into LinuxMint 12 from GRUB after a restart.
I also figured out that it appears that GNOME is what I was seeing. I think I was using KDE before, but its gone, I think. I'll mess around with different desktops to see if I can get the original back.
Any ideas what might have happened?