This is an exciting month for service packs. Note the separate download for Windows Server 2003

Microsoft .NET Framework 1.1 Service Pack 1 [for Windows 2000/XP] <http://www.microsoft.com/downloads/details.aspx?familyid=A8F5654F-088E-40B2-BBDB-A83353618B38&displaylang=en>

Microsoft .NET Framework 1.1 Service Pack 1 for Windows Server 2003 <http://www.microsoft.com/downloads/details.aspx?familyid=AE7EDEF7-2CB7-4864-8623-A1038563DF23&displaylang=en>

Microsoft .NET Framework 1.0 Service Pack 3 [for Windows 2000/XP] <http://www.microsoft.com/downloads/details.aspx?familyid=6978D761-4A92-4106-A9BC-83E78D4ABC5B&displaylang=en>