This version has not been uploaded yet, AFAIK. It was the first 32-bit version of Windows, and even predates the Windows 9x Series! The floppies must be write protected before being inserted, and the CD-ROM must be dumped with Alcohol 120%.
3.10.511.1 Windows NT 3.1 build 511.1 is the RTM of Windows NT 3.1 Setup doesn't detect processors newer than the original Pentium, as well as some models of 386, 486, and Pentium processors. To bypass this, two INF files must be edited after the first stage (in text mode) of setup is done. Change the line STF_PROCESSOR = "" ? $(!LIBHANDLE) GetProcessor to STF_PROCESSOR = $(ProcessorID_I586) in INITIAL.INF and SETUP.INF files in the SYSTEM32 subdirectory of the target installation directory. If you're doing this on a 386 processor use I386, and for 486 processor use I486 instead of I586.