1) This is a function of the Toshiba Recovery Disk the default is to restore the machine to its "out of the box" state
Vista's self-recovery is the closest equivalent to XP's repair/reinstall.
However you should have an option when booting to the DVD for "Repair your Computer" at the Vista screen.
This is designed to fix start up errors but the XP type function to refresh system files isn't available in Vista :(
Best alternative is the System File Checker (SFC) which will replace damaged system files.
2) As there is no "repair" option like XP this question is a little redundant but the only legitimate ISO downloads are from the Microsoft Technet and MSDN sites to registered subscribers. Not helpful in any event as you need to have the Toshiba OEM version to keep your license activation happy.
This closed question has some links that might help you at least get the start up error fixed.
http:Q_23731263.html