I restored my system from a Windows System Restore point. It solved some issues I was having, but introduced other strange problems (like my optical drive disappeared).

One thing that surprised me was several files from my Web2Py installation were deleted: the executables and *.js files; possibly some others (like favicon.ico). I did not expect this because Web2Py is basically a portable, standalone application. You just unzip it and run the executable inside, so nothing should be registered with Windows. My question is: what files does Windows system restore delete, and how does it decide this? I'm just wondering what other files I'm missing and if there's a way to get restore them (without rolling back the restore point). Perhaps it scans for certain files types (like exe, js, ico, dll) with a creation date that was after the restore point creation date?

Some other people who experienced a similar problem:

• Dropbox: Lost Files
• User files missing after run system restore.

update: I found some more references on how Windows System Restore works:

• Understanding how System Restore in Windows Vista treats executable files
• Why Vista's System Restore is Dangerous and What to do About it