So, I have a Portege M400. I ordered recovery media which is Win XP Tablet Edition on DVD, the 2005/2006 version. Initially, I kept getting the cannot identify message which would error out to "WRONG MACHINE" on the third try unless I typed in "Portege 400M" which I'm assuming was the proper thing to type as the model. When I do, however, I get the "Model Number Cannot Be Saved" message and it re boots.
Support told me this was, as I figured, a DMI issue. Problem is, I can't reset the DMI. I've updated the BIOS to 3.8 but the BIOS update utility and the DMI utility are two separate things as far as I can tell. There is no DMI utility listed under the downloads section of this laptop and all the links to the DMI update utility, toshdmi10.exe, give applicable models of which mine is not one of them.