http://www.dougknox.com/security/scripts_desc/regtools.htm
You can download a script here for the Registry
See also:
www.dougknox.com, Win XP Utilities, Windows XP Security Console

Wouldn't hurt to do a security check from one/two of any of these

Symantec
http://security.norton.com/sscv6/default.asp?langid=ie&venid=sym
Trend Micro House Call:
http://housecall.trendmicro.com/
Panda ActiveScan;
http://www.pandasoftware.com/activescan/com/activescan_principal.htm
McAfee FreeScan:
http://us.mcafee.com/root/mfs/default.asp
Kaspersky Labs On-line Virus Checker:
http://www.kaspersky.com/remoteviruschk.html
BitDefender Online Scan:
http://www.bitdefender.com/scan/licence.php