WIN XP HOME EDITION

MY COMPUTER FREEZE DURING THE UPGRADE FROM ME TO XP. THIS OCCURS WHEN THE REGISTERING COMPONENTS IS GOING ON AND TIME LEFT IS 20 MIN. AVAILABLE MEM. IS 256 MB AND AVAILABLE SPACE ON HARD DRIVE IS 1.5 GB. REMOVED THE MODEM B/C XP WILL NOT WORK WITH IT. STILL SAME THING IS HAPPENING AGAIN AND AGAIN. MICROSOFT SUGGESTED TO UPGRADE THE BIOS WHICH MIGHT WORK. PLS HELP ME WITH THIS SITUATION.
THNX
NTGUY