Installing Windows NT 3.1 on Qemu
Windows NT 3.1 will install, however it does not have PCI support so you'll be restricted to the ISA machine. Also NT 3.1 cannot drive IDE CD-ROM's. So you would have to follow the network installation guide.
When NT 3.1 was released pentium CPU's were still beta, and the cpuid thing had not been finalized enough in the install script. You will either have to have a version of Qemu that can fake being a 486 cpu, or fix the setup.inf script to always install the 486 path.