Help me uninstall Avast Internet Security PLEASE!!

Upgraded to free trial of Internet security and computer started playing up - Chrome tabs in constant ‘busy wheel’ and unable to use the Start Menu because the task bar also showed same ‘busy’ symbol. Tried to uninstall Avast but it didn’t come off clean. Won’t let me reinstall until I get rid of other one. Had to do system restore because partial uninstall caused internet device drivers to corrupt. I’m not that smart with these things and have been struggling for two days. Am in Uk so can’t afford to telephone US support. PLEASE HELP ME!!

http://www.avast.com/en-eu/uninstall-utility

and important when installing AV …never install more then one
General: Uninstalling a third-party antivirus software http://www.avast.com/en-eu/faq.php?article=AVKB11#artTitle

Thank you I will try that. I never meant to install more than one. I believed I had uninstalled the first and was trying to replace it. Two further questions. How do I start Windows in Safe Mode and how do I later put it back into normal? Thanks for your swift, helpful response.

long time since i used the tool, but i belive the tool will ask you to start in safe mode and when you click yes it will start in safe mode
after you have run the tool you reboot and it will start in normal mode

if not. just google how to start (your os…vista,xp…) in safe mode and you should get a million hits, same if you search youtube for video…

Okay, thanks for your help