|Whether AVG works properly or not probably has absolutely nothing to do with whether you can "get on line with my PC"|
Are you getting an AVG related error message ?
What do you mean by "get on line with my PC".
Get the internet to work ?
If yes, are you trying to connect via a wired network connection (network cable) or via a wireless network connection ?
If you can't get AVG's own Un-install to work properly - I have no idea where you find that on a MAC - that's at Control Panel - Classic view - Add or Remove Programs in XP - the AVG web site has an AVGRemover program for Windows systems for AVG 2011 -it probably has one for Mac systems too.
NOTE that if AVG installation is corrupted, the AVG remover program may seem to stall - it probably hasn't - WAIT at least 5 minutes for it to complete.