Good luck with that. Even after deleting it the right way(through the Uninstall process) it still leaves all sorts of clutter. But at least with their uninstall it does cease to function for the most part.
When using a spyware app to delete it didn't work so well last time I tried, but it can be done, eventually.
You can 'try' these online scanners and hope for the best. Depending on the speed of your system and how much data you have it can takea few hours to a day for some of these scanners to complete a scan.
http://www.trendmicro.com/spyware-scan/
http://www.ewido.net/en/onlinescan/
http://safety.live.com/site/en-US/default.htm
If Zango is still in your 'Add or Remove Programs' area, you might try to uninstall it that way.
It might just be quicker to install Zango again if you can, and then use the 'Add or Remove Programs' area to uninstall, and then run a couple scans to clear the junk they leave behind.