I used the windows cd to boot and restore the system to an earlier time, but first I found out in the bios that the usb keyboard was not enabled, so when i first tried to boot through the cd i had a problem since it asks if i want to boot through the cd i should press any key, and i wasn't able to do that since the keyboard didn't work.
I also used a regular usb keyboard and not my cordless one (the cordless keyboard still doesn't work at startup even though it is usb, any idea why?).
so lastly: how can I activate the guest account without the same bug happening again? should I create another administrator account just in case?