firefox?

We recently got a message, after firefox (automatically) updated, that we should immediately update flash player because of a security threat.

A friend of ours didn't do that and waited one day. The next day her computer had seemed to be rewritten as if windows xp was just installed. There was no mail and no settings in Outlook Express as if it had been run for the 1st time. Super Antispyware ran as if it was the 1st time also. I don't know how many other programs are going to be like that.

I didn't see much on google about this so far.

 

That doesn't make much sense. It would have had to download a virus that will delete everything.

Possible causes:

1) A virus
2) Factory restore
3) Shutting down by unpluggin sometimes can cause this. But not the deletion of emails. (if I unplug my computer while I have Firefox or Visual Studio running, I get the first time wizard)