No one is entering your computer and changing the game settings. It cannot happen.
There are a ton of other reaons why this would happen.
Virus programs, anti-virus programs, spy sweeper programs, spyware/malware could all contribute. Also, running Windows restore could do it (not actually doing a restore, but using it and then having a virus/spyware/malware program infection which could cause restores to happen without you wanting them to).
If your computer is rebooting and settings are being restored, it is more than likely due to some program causing files to be write-protected and Windows not being able to save the files. Anti-virus and spyware programs can cause this, along with a couple of nasty viruses currently loose on the Internet.
