Look for Lop in Add/Remove programs, or run their uninstaller program:
http://66.220.17.157/help.html
The uninstaller itself is flagged as malware by several scanners at VirusTotal, but I’ve used it myself in the past to remove a lop infection that Spybot/Ad-Aware wouldn’t touch, and it did what it promised to do.
No guarantee that it is still trustworthy, though…
