Im not sure if this can help, but since I've bought one of these GREAT machines (A Stylistic P600, to be exact), and spent like three weeks in trouble before figuring out how to solve the problem of reinstalling correctly windows on it, I'd like to share my quick and easy solution.

simply, I spent 9$ to buy on Ebay (here is the auction: Installazione Windows - Fujitsu Stylistic C-500 e P-600 su eBay.it Fujitsu Siemens, Computer portatili, Informatica e Palmari ) one very cool Restore DVd which allowed me in 5 minutes (even less, maybe three!) to install Windows 2000 and/or XP together with EVERY driver, and additional handwriting recognition softwares.
Since im not the seller, and i think this is a very open problem, I'l share the address to which I could buy the Item (BTW please note that he told me that he has a limited amount of these restore DVDs).

The only thing I needed was to unscrew my Tablet hard drive and mount it into a USB external drive (this operation took 1 minute), then start the Image software, which actually copies the hard drive image on it, and voilà! Everything works from then and I'm super-happy user of XP (which seems to run reeeeeally lighting fast, as contains also many optimizations ofr this particulara device).

Seller is Italian but could answer me both in English and French.