[TippeX]

i'd suggest uninstall avg, download the new one (think its v9 now, was available yesterday when i checked) and reinstall it, something is obviously very wrong.. and it might also be a good idea to try scanning your pc for trojans / rootkits, as it could also be some trojan / rootkit / virus blocking avg... so perhaps scan using an online scanner (takes a bit of time, but its better than nothing), but first try uninstall, download new ver, reinstall, if that works, then i'd do a full scan.. good luck