avg antivirus skrewed my win7

Hi

well, i installed win7.
i customized my desktop & all...
i installed comodo firewall & avg antivirus. & after i restarted my pc all my customization was gone!

i got the normal aero theme & all (that i previously canceled)... + the system didn't allow my to run almost anything by saying something like "your current internet security settings prohibit running....." or something similar.

so i uninstalled comodo firewall to check if this is what skrewed me. & no. so i uninstalled avg - & yes. this was the one. i now can run things. but for example when i want to customize mt desktop icons & show my computer on the desktop - i can't! i click it but nothing happens. so i enter the persenolize menu again - & the "V" that i checked there near show my computer is unchecked...

how to set it to be good again?
thanks