spybot should work fine on nt4 havent checked recently but i know that 1.5 had 95 support however i havent tried spybot on nt4 for ages but it should work EDIT: Supported OS: Win95, Win98, WinME, WinNT, Win2000, WinXP, Win2003, WinXP64, Vista, Win2008, WinPE