Download the appropriate file for your platform. Intel filenames end with i, and Alpha updates end with a. Select standard or high encryption as necessary.
- Main Windows NT 4.0 download page
http://www.microsoft.com/ntserver/nts/downloads/default.asp
- Service Pack 6a (SP6a) download page
http://www.microsoft.com/ntserver/nts/downloads/recommended/sp6/allsp6.asp
- SP6a hotfix: Upgrades SP6 to SP6a
http://download.microsoft.com/download/winntsp/patch/6.0a/nt4/en-us/q246009i.exe for Intel, http://download.microsoft.com/download/
winntsp/patch/6.0a/alpha/en-us/q246009a.exe for Alpha
- Compaq Alpha hardware abstraction layer (HAL) and firmware updates
http://www.compaq.com/support/files/alphant/firmware