If she doesn’t have a Vista DVD, she (you) can download and then create a Recovery Disk ISO here click here Try to avoid the torrent as it may be slow. From the ISO image on your hard disk, create a CD (a DVD is not necessary as it’s only 120MB).
It works in the same way as the Vista DVD, i.e. boot from the disk, choose ‘Press any key to boot from CD/DVD’ and Vista will start to load the Windows files. Select your language, time/currency and keyboard then click ‘Repair’ in the bottom left corner. Within the repair option there are five choices: Startup Repair, System Restore, Backup Restore, Memory Test and Command Prompt.
This CD will also boot to an XP installation and allow the Command Prompt option to run programs like chkdsk.