Earlier today, I rebooted my computer. Partway through the boot process, it shut down suddenly. When I tried again, I was prompted to run Startup Repair, and I did. Afterwards, my computer booted normally and everything seemed to be in order.

Then I noticed that my My Documents folder contains a mix of old and new files. On closer inspection, it appears that Windows has reverted my system to a previous state. Two things puzzle me:

1) According to Microsoft, "System Restore does not affect personal files, such as e-mail, documents, or photos [...]", yet many of my personal files have been affected.

2) Why were some things reverted, but not others? I had recently reorganized a bunch of files in My Documents. The reverted directory structure seems to be a hybrid of old a new, with a lot of new stuff missing. It's hard to say for sure, but it looks like the stuff that's missing would have been in conflict (two folders with the same name, for example), and Windows favored the old stuff.

Is this normal behavior for Startup Repair/System Restore? To modify personal files, I mean? Is there a pattern to the mess it's made of My Documents?