I have never had a PC show up with a bogus user account. My email account has never dissappeared. I have had kids purposely infect a computer with spyware and virus' trying to be funny. Rather than spend hours trying to rid the system of spyware and virus, I just wiped the drive clean and did a fresh install. In your case, even if it did not mean a virus caused the problem, having a bogus user account and important things like an email account dissappear would cause me to seriously consider reinstalling the OS to make the corrections. But then I will reinstall my OS if I feel even the smallest corruption or malfunction I can not fix regarding the OS/registry/etc.