ClamAV For Windows 0.85-1 for Win9x/NT4/ME/Win2k/XP (4.36 mb)
avast! 4 Home Edition 4.1.260 for Win9x/NT4/ME/Win2k/XP (7169 kb)
AVG Anti-Virus Free Edition 6.0.465 for Win9x/NT4/ME/Win2kPro (5 mb)
AntiVir Personal Edition Ver 6.13.00.xx for NT4/Win2k/XP (3.9 mb)
All these work with Win2K and NT
go here : *www.k7v.com/nonags/antivirus.html
or try this
a-squared (a2)Freeware 98, NT, 2k, Me, XP, 2003
More info
This program scans your computer for malicious software.
Sorry this is only Freeware i cud find......But there are bunch of Sharewares that run on 2003 here:
*www.tucows.com/downloads/Windows/Internet/Anti-virusScanners/