LiveCDs... yeah... absolutely a must-have for anyone who wants to be able to fix their own computer problems no matter what they are.  One thing to watch out for is the NTFS file system - if your hard drives are formatted as NTFS you should make sure the LiveCD OS can read and write to NTFS.  If it's a windows based LiveCD it shouldn't be a problem but not all Linux based LiveCDs can read and write NTFS formatted partitions.  That's all I think I can add and only because whenever I've needed to use a LiveCD for troubleshooting it was because there was a problem with the Windows system drive that made the computer unbootable to begin with.  Great post and info :)