All Imaging software allows you to make a Boot CD which restores the latest Image without Windows. This is the easiest way to recover but requires you make regular images.
An XP Retail CD allows you to boot into the Recovery Console if F8 doesn't work. Google 'how to make xp disk' if you don't have one.
Utility CDs such as Hiren's or ultimate Boot CD can fix a myriad of problems (manually)
I find Partition Wizard Bootable CD useful for quick MBR fixes and recovering wayward partitions.
An Ubuntu Live CD is useful for getting data off a drive.
All the major Anti Virus vendors have free Emergency/Boot/Recovery Scanning downloads.