I'll let you in on something, if that Toshiba web site is telling you that your Operating System is not supported and is not offering up anything to you, try something I used to do when my old Toshiba x205 laptop was working. Fool the web site in thinking your running Windows Vista! Select Windows Vista as your Operating System, but be careful here, only select the proper (bit) option. If your running XP (32bit) then only select Vista (32bit) and the same is true for the (64bit) stuff, 64 goes with 64, you know what I mean. Try that a couple of times and see what happens, for me when doing it this way I had very good luck in installing Vista designed drivers for my Windows XP Professional (64bit) system.
So please try this way and let us know what happened!