What should i do first?

Im planning on upgrading my current computer, a sony vaio (specs below) and wonder what i should do first, as i currently dont have the money to build a new pc.

p4 3.0 w/ HT (sum stupid built in thing with this mobo wont let me oc it )
512 pc3200 ram
geforce fx 5200
230 watt psu

what i have already:
creative inspire p7800 7.1 speakers
audigy 2 soundcard
saitek eclipse keyboard
sum cool blue led microsoft mouse (im thinking about getting a gaming mouse tho, this one just matches my other lights lol)

thanks

 

i consider myself a gamer, although my rig doesnt exactly have "GAMER" written all over it. I have my lil 5200 oc'd as much as it can go and surprisingly it has no artifacts. As far as the psu goes, from what i have seen in pictures mine looks really small compared to them. And my case kinda has some brackets that would limit the size of the psu but i might be able to do some modding to get it to fit if it doesnt already. Ill try to get some pics to show u.

 

Yeah, some of the Sony's can be really "tight inside. I have one I use just for gaming (see sig). I'm running a Nvidia GeForce4 Ti4200 (128)AGP in mine, and it games like a dream. I still have the original P.S. in it, and haven't had any problems with it. It has like a 5" fan on the inner side of it, rather than outside like most. And that fan is about 1" away from the processor fan (which MUST be pulling air AWAY from the heat sink, rather than blowing into it. Otherwise, there's an air flow direction battle. If you want to change the P.S, you'll have to measure it, and visit manufactures sites, and get dimensions of their units. I'm sure with enough surfing, you can find a fit.
Also, check your harddrive RPM. If you got a 5400RPM, like most stock ones are (mine WAS), an upgrade to a 7200RPM with a nice 8MB cache will eliminate a huge bottleneck for ya.