As a start, try one or all of the following free online scans, get rid of whatever they find:
A-Squared On Line Trojan Scan -- http://www.windowsecurity.com/trojanscan/
BitDefender On Line Scan -- http://www.bitdefender.com/scan8/ie.html
Ewido On Line Scan -- http://www.ewido.net/en/onlinescan/
F-Secure On Line Scan -- http://support.f-secure.com/enu/home/ols.shtml
House Call Anti-Virus http://housecall.trendmicro.com/housecall/start_corp.asp
My wife says her Dell Inspiron E1505's Win xp desktop disappeared, and she had a new one that is not the same and could not find her e-mail. I checked. True. Her user account no longer has any documents in it at all (she is a profuse e-mailer)and even the Outlook Express program does not show up in her program list. Most of her very many desktop icons/links are missing as well. I opened up the system admin. user account and found that Outlook Express shows up in that program list and it works; so it is still in the computer. I have tried to restore the computer in her user name twice using different reference times, but even the previous day's set-up is not there. Anyone have any ideas? She wants to throw it away.