Spontaneous settings restore and data lost after hard shutdown

Hi,

Something really strange happened to our laptop. Working normal until my wife was shutting it down. She closed the lid after initiating shut down. After it never shut down, she opened it up and did a hard shut down. At next restart, she was prompted to enter safe or normal mode. She chose normal mode and the computer started but many settings were reverted to what they were several days ago. First thing she noticed was wrong was her desktop background was a previous one. Second thing was that her Outlook account was erased and outlook no longer sends/receives emails. (I just loaded her pst file (outlook) into Outlook 2007 yesterday and it worked fine for a day until this incident...now her outlook folders and old emails are intact, all emails received AFTER I loaded the .pst are gone, in addition to her account settings).

There may be other things amiss, but this freaked us out and, thinking this is a virus, we just shut the thing down)...reason for the virus paranoia? We just copied to this laptop tons of files (no .exe files I think, all data) from a computer that is infected with a virus related to "Ophcrack," in an effort to save files on that systems before we totally wipe it; I didn't think that all files on a pc were necessarily infected if the machine was running a virus.

We don't know where to start. Can anyone help us start to narrow the problem down?

Thanks!

Thanks Steve. I ran Malwarebytes, Spybot and AVG scans and didn't find anything major. The system remains stable, but erratic behavior remains in Firefox. It spontaneously shuts down after the first few clicks on a website. Any other thoughts?