after starting up with the Disc, use the utility included in the Disc to re-install. It is surprising that you still got a Disc. Usually it is a partition called out by pressing F8 key
http://www.geekpolice.net/t18281-toshiba-recovery-partition-hotkey-instructions
Of course you need to figure out if it worth the time to reinstall. Maybe you can start in safe mode by pressing F8 when you see Windows' logo.
