I was cleaning out some stuff in storage and ran across a Windows NT 4 Workstation CD (in original jacket). On a whim, I made an ISO of the CD and actually got it working under VirtualBox 4.0.6 running in Windows 7 x64 Ultimate w/SP1.
Windows NT 4 wouldn't recognize a 8GB virtual disk drive, so I made it 4GB with an assigned 1GB of ram and 32MB of video.
Total installation time was less than 15 minutes on a quad core w/8GB of ram.
The built in browser is Internet Explorer 2.0
It does require a valid CD-KEY to install NT Workstation 4, just in case you were wondering.
If anyone needs help in this area, please let me know (I'm just tinkering here).