I can't give you direct links to download this driver because of the Fujutsu website design. You have to start here:
Then select your pc from the drop-down menu's. Once you get to the download page, select Windows XP from the options (near the bottom of the list). Then click on the + button next to Audio to expand the options.
Download and install the matching KB888111: High Definition UAA driver
first. It's available in German and English. Be sure to get the KB888111 driver that matches your exact Windows XP version, ie: SP1 or SP2. There is none for SP3 so if you have that version of Windows, try using the SP2 driver.
Then download and install the regular audio driver, ie: VT8237A embedded / VT1708A codec