I have a dual boot system running Windows7 and Mint 13. Somehow, long story (I tried to uninstall my LAMP server in one go) I managed to delete my login managers. I tried to boot in text mode and install one but I didn't get a login prompt. Next I tried recovery mode, but when I try to enable networking the system hangs indefinitely while mounting the file system. Next round, live USB disk (getting CD's is a hassle at the moment.) Any other ideas?
You should be able to get a bash prompt you should be able to add the following to the end of the line which says "kernel"
This will bypass all the login scripts and give you a bash prompt (as root). With some luck you can then fix your disk problems, then reboot in text mode, then install your Window Manager from the command line.
Another possibility (if you are lucky) might be to boot the system and see if you can switch to a text console (try X) where X is each number between 1 and 7. With some luck you should be asked for a login on at least one of these terminals, and then install the manager.