MS Windows Malicious Software Removal Tool, MSRT, is a free download that can do a quick or full scan along the lines of Malwarebytes.
I think it gets security descriptions via monthly MS Tuesday patches.
IT guys....Do I need to run this, or is it already automatically being done by the OS???
Meaning there was no need to download it as Windows KB890830-V5,9.exe
Pretty sure MS recently said something about continuing, not just MSE, but also sending the Tuesday security info that MSRT needs.
If I am on the right track, and if you trusted that MS does not need to have excessive reports of virus infection and malware, then with the MSE antivirus and MSRT malware detection/removal, an XP user actually has credible security measures in place.