Ubuntu Installation :: Restarts On Boot After Upgrade?

I had perfectly working lucid on my laptop (64 bit) which I installed from a live CD not wubi. I tried to upgrade with update-manager and everythingooked fine until I accidentally updated compiz from the cache before everything else finished. this made compiz stop working completely, which also broke metacity. I tried to fix this with multiple things: Downgrading compiz (failed to apply changes), sudo apt-get install -f, finishing the upgrade (see the following).

during the applying changes stage of the upgrade i got an error with almost every package it tried to apply (sorry I don't know what, but it said something about 'this package failed to upgrade and may be left in a broken state'. I let the upgrade finished and at the end it said 'Upgrade Finished but not all changes were successfully applied' and I shut down the computer. when I turned it back on everything looked fine until I past to the usplash screen. Then the screen went black, a bunch of error messages scrolled by too fast to read, and my system rebooted.

I tried recovery mode and another kernel choice at grub but all did basically the same thing. Windows still works as much as it usually does but I want my ubuntu back! I am OK with doing a fresh install if I can somehow recover a small amount of my data in my home folder. If you can tell me how to get into ubuntu from windows or something that would be great but I also need to know how to decrypt my home folder (I used the encrypting option in the installer)