I've got a b120 as well and you do have to wipe the harddrive of bloatware if you want any usable space. You're just supposed to download all available drivers first and copy them to usb or CD first!!!
Here's the location @ Dell:http://support.dell.com/support/downloads/driverslist.aspx?c=us&cs=04&l=en&s=bsd&ServiceTag=&SystemID=INSPIRON%20B120&os=WW1&osl=en&catid=&impid=
download each of the newest ones from each category onto your USB and you can execute them from there. BTW, dell wireless utility SUCKS. You're better of just using the wireless configuration built into xp.