Service Pack 6a (US) for NT 4.0 - High (128Bit) Encryption 
Service Pack 6a (US) für NT 4.0 - Standard (40Bit) Encryption 
This Kit updates your Intel Based Computer running
NT Server 4.0 or NT Workstation 4.0
Updated Version !
This Update includes the Patch for Service Pack 6 !
Readme for Service Pack 6
Size: 34 MB

Service Pack 5 (US) für NT 4.0 - Standard (40Bit) Encryption 
This kits includes NT Service Pack 5 for your Intel Based Computer running NT Server 4.0 or NT Workstation 4.0
Size: 33 MB

Service Pack 4 (US) für NT 4.0
This Kit includes NT Service Pack 4 for your Intel Based Computer running NT Server 4.0 or NT Workstation 4.0
Readme for Service Pack 4
Size: 73 MB

Service Pack 6 (US) für NT Terminal Server 4.0
This Kit updates your Intel Based NT Terminal Server to Service Pack 6
This is NOT the same Service Pack 6 as the above mentioned SP6 for Windows NT 
Size: 37 MB

Service Pack 5 (US) für NT Terminal Server 4.0
This Kit updates your Intel Based NT Terminal Server to Service Pack 5
This is NOT the same Service Pack 5 as the above mentioned SP6 for Windows NT !
Size: 29 MB