New computer, but...it sucks?! what do i need to make this a

this is my Dell that i bought, obviously there can be improvements, so, let me know what items i should be upgrading...

Dimension 9150
Pentium(r) 4 Processor 540 w/HT Technology (3.2GHz, 800FSB),
Processor:
Pentium(r) 4 Processor 540 w/HT Technology (3.2GHz, 800FSB)
Memory:
1GB Dual Channel DDR2 SDRAM at 533MHz- 2DIMMs
Video Cards:
128MB PCI ExpressTM x16 (DVI/VGA/TV-out) ATI Radeon X300 SE HyperMemory
Hard Drives:
160GB Serial ATA Hard Drive (7200RPM) w/DataBurst CacheTM
160S

Of course the video card isn't that great. actually, i have no idea, it could be terrible, the whole system could be terrible.

what potential upgrades should i consider if i want to play games like

elder scrolls 4
FEAR
etc?

there are some cheap vid cards floating around, specifically
X850XT PCIe Radeon video cards by Sapphire

is that good enough to make my system good?

thanks

edit: is the vid card i have worse than a geforce 4?

you bought a pc with those parts?? hm...was it a while ago? to be honest i think buying ps'c is just a waste of $$(thats just my opinion), its much beter/less expensive/and beter quality wise to build a system urselfe.
lol and i c u are a gamer lol....the radeon 850 series is ok the clocking is ok, but to be honest i would get a system, or atleast some components that would last a while, ....so you wouldnt have to get a new gfx card just for a new game, and then in what half a year/year when a new game comes out you would be running to the store for a new card(its a waste of money) ...have you thought maby of geting a atis 1800 or 1900 series cards?...if you are looking at it budget wise, sometimes its beter to spend a bit more for a beter product, than be skimpy, and then go spend more for a new product later on. im also planning to build myselfe a new rig, but with the prices now and vista being postponed i ll wait till atleast summer, or nex tyear...maby.