But the real issue is your're trying to run games on a laptop ! Most laptop LCDs don't refresh fast enough for good gaming; you're running out of disk space and laptop disk space is high cost relative to desktop hard diskspace and you don't have enough RAM.
So before investing another dollar in that underpowered unsuitable for gaming laptop....think hard about putting the $$ you'd spend upgrading it toward a separate modest gaming machine.
Tske a look here for some suggested systems
I have a 2003 inspiron 5100 notebook with a 2.4 p4 processor, 512 mb ram, 80 gb hitachi HD.lately, (after installing doom3 and half life2) i noticed my hard drive is at around 70%. these games run slow i thought about getting and external hard drive to store some of my data. OR more RAM to speed up the games. what would be better for more performance???
also, on the hard drives my head is spinning. I want around 200Gb. but should i buy an external drive or buy an internal drive with an external kit? my pc is a IDE Ultra ATA....do i get this? or a SATA? if so Do i get a SATA, SATA-100, SATA 300, etc. i know 7200 rpm is good, but do i need 8mb or 16 mb?????? IM LOST. I wish someone would TELL me what to buy. if you help i will be forever grateful.