hard drive partition

Hi I am new to XP and after loading it on a new computor
with two hard disks, It seems to have created a third
space for its self (Local disk E). Now I am constantly
being told that drive E is low on disk space and when I
try to load other drivers and soft ware it tries to place
them in drive E and canot for lack of space. Now the
other drives are empty so I would like to use C drive as
default storage and drivers ore expand the limits of
drive E. Thank you for any help. David