button mouse config?

Due to few problems i re-formatted my hard drive then i
installed Windows XP on my Dell Lattitude laptop, now the
button mouse does not work. at first it would disappear
off to the top righthand side of the screen even with the
touch pad or PS2 mouse plugged in. right Now though the
touch pad works ok but the button mouse refuses to do
anything. Is this a software or hardware problem? what
shoulkd i do? any help would be appreciated. Thanks!!!