“What you should know about Volume Shadow Copy/System Restore in Windows 7 & Vista (FAQ)”
I found this blog post to be extremely insightful concerning the inner workings of Windows, as far as the Volume Shadow Copy and the system restore features go. If you’re concerned with the privacy/security of the files on your Windows machine, this may be a good read for you. Opening up various files includes the creation of separate temporary files and many bread crumbs. Knowing exactly how Windows handles this data is paramount when working with financial, medical, and other private data, or corporate trade secrets.
It may be too deep for many people to even care about. In any case, here’s the link.