You prolly already know about this, but just in case - sometimes brands create drivers for the OS that came released with the machine and over time later OS's, but sometimes they don't make drivers for earlier OS's.
I assume you have all the drivers necessary? Hopefully Toshiba has them available for XP? If not found at Toshiba maybe you can find a forum or something similar where other people with the same model have gone through the trouble of assembling/listing all necessary drivers.
That's the only thing I can think of off hand. Best of luck to you.
