This method will work on both NT Server and NT Workstations. To add HPFS support in NT 4.0 do following steps:
1. Copy PINBALL.SYS from NT 3.51 distribution to NT 4.0's SYSTEM32\DRIVERS directory.
2. Add the following Registry Key to the system:
3. In the above key, add the following values:
ErrorControl: REG_DWORD: 0x1
Group: REG_SZ: Boot file system
Start: REG_DWORD: 0x1
Type: REG_DWORD: 0x2
4. Reboot the system
Once the system has finished rebooting, the NT system should now be able to read/write to existing HPFS partitions.