At my wits end here so any help appreciated.

Running XP pro. sp3

My PC was working fine this afternoon until I updated my Norton Internet Security Subscription then it all went wrong.

Basically I started getting outgoing email popups from norton saying it was scanning messages etc (No email software was running so obviously a virus? trying to send)

Anyway norton finished updating and requested reboot.

PC rebooted but only gave me desktop image with no functionality

Help power button down to turn pc off.

Turned back on and it booted in following order
asus mobo screen
black screen with blinding cursor in top left
win xp loading screen
flashes blue screen then goes back to the black screen where you can select safe mode etc

Issue is that I really dont want to format and reinstall os.

Not sure but from what have read I may be able to resolve the issue by scanning pc from symantec site, HOWEVER

I have no way of connecting to the net as only option that will work if SAFE MODE

Safe mode with networking won't work (Just tries to load and ends up at same screen)

I can't do system restore (Gives me an error sayng not available in Safe Mode)

Normal mode does the same as when you try to boot from scratch obviously.

I also tried using xp disc to repair but no success (Received following error

setup cannot set the required win xp configuration information. This indicates an internal setup error. contact your system adminstrator)

Have run norton Scan from SAFE MODE and found vundo trojan. I downloads fix from tribune.org and didn't pick anything else up.

Any help appreciated.

Hello confuzzled1 and welcome to the PCHF

If you can uninstall Norton and see if that helps. Also did you noticed the blue screen error codes? Please provide some more of your computer spec's.
Do you have 2 anti virus programs running? Lastly if you can get your computer to run in a functional way,please look at the bottom of my sig and click on my prework link and follow the instructions,since your Scan said it found a virus...

Also this may have to be done one step at a time to eliminate your problem.....thanks for your patience

Hello confuzzled1 do you still require help?