If you install the NTOP on a Windows NT 4.0 computer that has Service Pack 4.0 installed, you will receive:
Setup detected that Windows NT 4.0 SP4 or greater is installed on your machine. We haven’t tested this product on SP4. Do you wish to proceed?
Just click OK and complete the installation.
After the computer has restarted, re-apply SP4.
The Windows NT Option Pack has been tested on SP4 and works just fine.