I would appreciate recommendations for cleaning up an XP machine that appears to have been infected with adware. I don't have a problem with buying a product for this.
I recommend two products good for this:
Ad Aware from Lavasoft.com.
Malwarebytes from malwarebytes.org
It's important you get these from the original vendor. For example, do NOT go to adware-2009.com (one of the paid links shown by Google if you search for "ad-aware"). That site's similar to the notorious "AntiVirus2009" site that loads you up with malware.