Hello serrato01,
my answer from another thread:
You can check Microsoft Windows XP boot troubleshooting or file C:\Windows\ntbtlog.txt from boot logging procedure to find faulty process, which is started after avgidsh.sys (mup.sys).
From last working solutions:
- mentioned checkdisk
- reverting unwanted changes in BIOS
What is the current situation?
Thank you
I've read through a lot of the post but they all are regarding Windows 7 or Vista and primarily x64. I ran into this issue on a Windows XP machine. I followed the steps the articles describe about renaming the AVG folder in C:\Program Files\ and also renaming any files that start with avg*.sys in the C:\Windows\System32\Drivers folder. But after doing that the pc will still lock up trying to boot. When I boot in safe mode the last item to show is the mup.sys. I don't think that is the issue. I also read that some people were having luck with running a chkdsk after so I'm in the middle of that right now. I will post if that fixes the issue but I have little hope that will fix the issue.
Can someone who has had this issue with Windows XP please advise. To include the most information, this is running on a Dell Optiplex 330, Windows XP SP2, we just upgraded to AVG2011 the day before yesterday and apparently it updated sometime today. The computer rebooted and just hung at the Windows XP logo with the scrolling green bar.
Thanks for the help in advanced.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic