Try to reboot to safe mode with networking and uninstall AVG as described here.
If it is not possible to even get into safe mode, please follow How To Disable AVG When The Operating System Cannot Be Started Properly.
When the system is bootable again, please provide us with MSinfo output and with installation log files so we can troubleshoot the issue.
Hi - I suggested to my friend he download this from cnet on his XP laptop. Since it restarted, Windows wont load properly. It gets to the desktop and it is blank - not even a start button. Any suggestions? Thank you