You can download it here:

ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/nt40/ussp4/


Here is the directory. Hope you have a fast connection:

10/21/98 04:18PM 154 128-BIT.TXT
10/16/98 06:03PM 42,890,808 NT4SP4A.EXE
10/16/98 06:00PM 32,767,904 NT4SP4I.EXE
10/16/98 06:00PM 31,926,680 NT4SYM4A.EXE
10/16/98 06:01PM 47,753,664 NT4SYM4I.EXE
10/16/98 06:02PM 90,970,000 NT4Y2K4A.EXE
10/16/98 06:03PM 76,403,536 NT4Y2K4I.EXE
10/16/98 02:27PM 98,749 README.TXT
10/16/98 02:27PM 102,316 readme128.txt
10/20/98 11:56PM 52,128 Y2KTESTA.EXE
10/20/98 11:56PM 35,280 Y2KTESTI.EXE


Most people probaby want the ones ending in "I" for intel.