to create setup boot disks do this:
To create a set of setup boot disks for Windows NT 4.0, you will need three 3.5" floppy disks and the Windows NT 4.0 CD.
Insert the Windows NT CD into the CD-ROM drive.
From the MS-DOS or DOS window, move to the CD-ROM drive by entering the drive letter followed by a colon (usually d: or e: ).
Change to the bootdisk directory by entering:
cd \i386
Enter the following command:
winnt32 /ox
The program should run and prompt you to insert your floppy diskettes for creating the set.
If you want to just create a boot disk go here
Mid page middle of the page explains what you need to do.