[masica]

I run a home-built dual boot system. Specs:
W2K Pro + all service packs current. Win XP Pro + SP 3. Intel P 4 2.4Ghz, ASUS P4B266-C mobo, 80GB HDD, 2GB DDR RAM.
On the W2K Pro partition, I have Avast AntiVirus installed with all signatures current. On the XP Pro partition, I have AVG with all signatures current. I also run Spybot S & D. I run FireFox on both partitions.
Iwas on the XP Pro system today and was booted off FireFox and my system rebooted. During a reboot, I always get the option to either boot to W2K Pro or WXP Pro. At that screen, I get a warning that I have a boot sector virus on my hard drive. I am advised to put a clean floppy in and reboot and asked if I want to continue.

Long story short, I was able to get past the prompts and boot up to W2K Pro. I ran my Avast AV and came up clean. I also ran SpyBot and came up clean. I was able to get back to the XP Pro partition and ran an AV scan a it found a couple things:

MsUpdate.exe and Trojan Horse downloader.generic7.AOVP

It also changed/cleaned up:

G:\WINXP\system32\kernal32.dll
\wsock32.dll
\user32.dll
\shell32.dll
\ntoskrnl.exe

The PC seems to work fine except for the 'boot sector virus' warning and prompts when I boot. I'm a bit reluctant to shut down at this point. Any ideas how to proceed?