Hi all

I'd appreciate some help on the following issue please.

I was on my computer on the net (windows XP and Firefox browser) when the Avira update box in the bottom right hand corner of the screen popped up. It said something about updating live toolbar and internet protection (from what I remember).

I said yes and it proceeded to start updating this and then seemed to crash Firefox halfway through. It also possibly crashed flash player too as images on web pages didn't appear anymore.

Anyway, the Internet wouldn't work anymore, so I restarted my computer. Windows now takes ages to load up.

When it finally does there is no windows menu task bar at the bottom of the screen. I did see it first time I restarted it and the start text on the button looked different, but now I don't see the button or toolbar at all. I do get desktop icons though. Then I get a 'data execution prevention' box come up.

If I close this not long after I get the NT Authority\System shutdown box, which will close the computer down in 60 seconds unless I run 'shutdown-a' command.

I can't access the internet at all. When I try to gte on Firefox it says there was a problem and it previously crashed, but if I say quit Firefox it won't let me do this and then get on it. Internet Explorer also won't work.

I can open up folders to view files, but I can't seem to run anything like mp3's for example.

I have read that it could be the sasser worm virus but when I look on task manager for applications that could be part of this I don't see anything.

Could it be something to do with a the virus update crashing and blocking any exe files running or is it a virus of some kind? Could it have been some kind of spoof update virus?

Not being able to get on the Internet means I can't download things to check it out. My Malwarebytes doesn't seem to work now and my Avira will open but doesn't work either.

If anyone can shed any light on what has happened or recommend a solution I would be very grateful! :) Thanks in advance!