was just getting the latest updates for ZA firewall and fell for a free scan they were offering, "SystemCheckup_ZoneAlarm2.exe" as I hadn't scanned my PC for a while. This is a sales gimmick as it scans but doesn't remove infections unless you pay.
Needless to say it says i have spyware on my PC so I've run my freeware sw, spybot and adaware with the latest updates - even did an avg virus scan and downloaded Spyware Doctor™ 5.0 for Windows from click here. Other than a few tracking cookies none of these detected any problems but the zonealarm software still says there's a problem!
How worried should I be and what can I do about it without paying?
I would do the scans the others have suggested and if they find nothing ignore it. There seems to more and more of this sort of scam going about and they rely on the fear they instill with the warning messages to get you to part with your cash. Sadly if you do part with your cash the chances are that it will not help things but make things much worse.