Vista Desktop would not boot after hitting AVG Firewall update button!

Hello Joseph,
We apologize for the inconvenience caused.
As you say that this issue happened after running the AVG update, in this case we suggest you to run the AVG Rescue CD and see if you are able to boot up your computer. Please use this link for the steps to download and run the AVG Rescue CD http://support.avg.com/SupportArticleView?urlname=How-to-use-AVG-Rescue-CD
Thank you.

On my Vista desktop, I uninstalled prior McAfee security successfully. 
Installed AVG internet security successfully. 
Established account successfully. 
Did steps for: Computer protection. It said: green Protected.
Restart was successful.
Did steps for Web protection successfully. 
Started Firewall steps, but after hitting: update, it did the restart sequence but WOULD NOT BOOT. 
NO OUTPUT AT ALL ON SCREEN. 
Tried several manual power down/power up under direction of AVG techs, 
even with Function F8: WOULD NOT BOOT. NO OUTPUT AT ALL ON SCREEN. case#03686488 - still unresolved.
Was routed to 3 AVG techs. Last AVG tech said he was not able to help further. 
He said I should post this to the community 
or contact my PC manufacturer or local tech support company(which probably costs major $s).

Joseph, Also did you download & run the McAfee total removal tool (http://us.mcafee.com/apps/supporttools/mcpr/mcpr.asp)?.
AVG Guru

Hello Joseph,
We apologize for the inconvenience caused.
As you say that this issue happened after running the AVG update, in this case we suggest you to run the AVG Rescue CD and see if you are able to boot up your computer. Please use this link for the steps to download and run the AVG Rescue CD http://support.avg.com/SupportArticleView?urlname=How-to-use-AVG-Rescue-CD
Thank you.