Sony_Vaio

My HD is partitioned so that I have C drive at 13.9GB (only 1.5GB availabe) and D Drive 98.2GB with 18GB available. When I try to install SP2 it tells me first that I am running out of space and I have tried to clear everything off the C drive possible with all apps installed on the D Drive. I am wondering if I will be stuck moving my partition which will probably cost me 40 bucks for software. I wish they gave me more room of the C Drive I dont know why they made it so tight ! Can anyone help with this ?