It is possible, but it ruins scalability. Use of one thread per client, is considered as old-fashioned, very inefficient programming (only few daemons does that - most use thread pools) It does offer better stability... but that's the only advantage it has over thread pools. Disadvantages are so many that I don't even bother to list them.
In otherwords: you don't want to see glftpd like daemon on windows; performance would be something between terrible and horrible, resource usage would be 1-2mb per client, proper synchronization of processess near impossible, and stability not much better that what it is with current core...
I think I have skill to port glftpd to run under cygwin nowdays... might even get it to compile under visual c++