Emulating Windows NT 3.51 in QEMU

1. Obtaining the Install Media

You’ll want the MSDN ISO for Windows NT 3.51 Workstation (July 1995 build). Verify its SHA‑1 hash against known archives (WinWorld, BetaArchive) and grab the three boot floppies (Setup Disk 1–3) to launch text‑mode setup.

2. QEMU Configuration

Emulate a late 486 / early Pentium box with IDE storage:

qemu-system-i386 \
  -cpu pentium \
  -m 64 \
  -hda nt351.qcow2 \
  -cdrom winnt351.iso \
  -fda setup_disk1.img \
  -boot a \
  -vga s3trio64 \
  -soundhw sb16 \
  -net nic -net user \
  -rtc base=localtime

• 64 MB RAM balances NT’s GUI & networking without excess.
• S3 Trio64 VGA ensures 800×600/1024×768 in 256 colors—no Program Manager corruption.

3. Installation Process

Boot with Setup Disk 1, follow text prompts, partition/format as FAT16, then insert Disks 2 & 3. The installer switches to GUI mode.

Tips:

• Select IDE CD‑ROM (ATAPI) drivers—QEMU handles it.
• Choose AMD PCNET NIC; drivers are on‑disk.
• Configure networking later with static IP; DHCP can stall.

4. Installing Video & Sound Drivers

Video

In Program Manager: Control Panel → Display → Change Display Type, pick “S3 Trio64”, reboot.

Sound

Select “Creative Labs Sound Blaster 16/AWE‑32” and set IRQ 5 / DMA 1 / I/O 220—matching QEMU defaults.

5. Networking

In Control Panel → Network, add TCP/IP and assign:

IP      10.0.2.15
Subnet  255.255.255.0
Gateway 10.0.2.2
DNS     8.8.8.8

User‑mode networking grants legacy web access. NT 3.51 handles IE 2 or NCSA Mosaic, but forget HTTPS.

6. What It’s Good For

• Peeking at NT internals pre‑Explorer shell.
• Testing 16/32‑bit hybrid Windows apps.
• Dusting off early Win32 SDK utilities.
• Running ’90s network diagnostics, capturing raw TCP/IP behavior.
• Software archaeology: installers, DLL trees, real‑mode shims.

7. Known Bugs & Glitches

• RTC clock drift—NT 3.51 + QEMU don’t always sync.
• SB16 crackle under host CPU load.
• S3 driver may forget resolution; reset via Display control.
• FTP trumps HTTP for file moves—spin up a local server.

8. Final Thoughts

Windows NT 3.51 sits in a nostalgic limbo: it looks like 3.1x but behaves like NT 4. Program Manager feels DOS‑era, yet you’re on a true 32‑bit, multi‑user OS. No animations, no fluff—just sharp lines of code meeting the understated UI of mid‑’90s enterprise computing. Running it today is less about productivity and more about opening a glass‑walled time capsule of pure, restrained design.