problem in AVG

Hi,
when I make a reboot and after my PC showing the desktop, it works for much time (3-4 minutes) before I can open a software or a folder. In this time my PC is inactive because the CPU is working. I think the problem is AVG Control Center, in fact when I open it I see the panel without the central icons. "AVG Resident Shield, Email Scanner, Internal Virus Database, etc, etc ...." They appear after a lot of time. In the meantime I hear my PC is working for them (3-4 minutes). I have a Pentium IV 2800 MHz and 1024 RAM and Win XP. Why have I that problem?
Thanks

My computer does not recognise the licence no which came with the cd.I am finding it difficult to download AVG 8 which I purchased on my computer on 28th AUG and which has already been taken from my bank . Please instruct me what to do next Ihave not recieved any Email messages at all.