How do I find viruses and other threats without using scanning software. I'm running a Dell Latitude C510/C610, model# pp01l, running Windows XP Professional version 2002 service pack 3. I've run scans from several different companies with no success. It has a 27.9g hd, 11.6g used, 16.2g free.

The bast way is to use scanner or Anti-Virus to detect and remove Malware or Threat or Virus. You could find location of Virus if you are familier with them but it will take too long and also Virus are conencted to other components and safer way to remove them is to do full scan .However, if you believe that you are infected then try the following link:https://consumersecuritysupport.microsoft.com/default.aspx?productkey=pcsafetymalware&faq=1&mytask=diagnosticsAnd do steps that it ask and file a support case.