Hello,
I have a TROJAN horse virus on my computer that was detected using AVG's free virus scan software. I was able to remove some of the viruses and there is one left that the AVG software was unable to get rid of.  It says Worm.Nachi B was detected. This is a very big PROBLEM b/c it is affecting my setup and internet connection -- It is not allowing me to SET up a firewall on my new ISP!! This has my computer shutting down on me at any given time when I am online due to some "NT AUTHORITY/SYSTEM" TERMINATION error. And when i boot my computer up, it takes a very long time to start. I have Windows XP and my pc is relatively new, so i shouldn't have these problems. What software/remedies would you suggest?

Thanks
Tiffani
PS please let me know if there is any other info you need.You could try to GOOGLE for the removal tool. Or you could visit the Symantec web site.  They usually have removal instructions.  If all else fails you could system restore to an earlier time.          HTTP://www.symantec.com/index.htm
Good Luck You may be able to remove the Trojan by running the virus scanner from Safe mode.