I second UBCD4Win...just had to use it this week to clean a really nasty 
virus+trojan+rootkit (yes it was all three!) off a machine.  UBCD4Win 
lets you boot a stripped down build of XP from CDROM, and includes a 
bunch of handy tools including antivirus/antispyware that can be updated 
from the internet (updates ramdisk) to get the latest signature files.

-Charles

JD Austin wrote:
> I build XP boot CD's so that I can scan the computer outside of it's 
> operating system.
> UBCD4Win is my current favorite.
> --
> JD Austin
> Twin Geckos Technology Services LLC
> jd@twingeckos.com <mailto:jd@twingeckos.com>
> 480.288.8195x201
> http://www.twingeckos.com
>
>
> Henny Youngman  - "When I told my doctor I couldn't afford an 
> operation, he offered to touch-up my X-rays."
>
> On Wed, Feb 25, 2009 at 9:02 AM, mike havens <bmike1@gmail.com 
> <mailto:bmike1@gmail.com>> wrote:
>
>     hey guys, I know that if you get a virus in M$ the best thing to
>     do is to reinstall the system. Would the next best  thing be to
>     install a copy of clamwin into their computer.?
>