FPS problems with brand new rig

Hello all.
I realize there are a lot off these topics (i have searched all over the net!) and Toms hardware seems to have the best community so i came here for answers.
okay so i have built a fresh new pc from scratch and i am getting less fps then i should. i have looked everywhere for answers and i am really disappointed because this is my first own rig i would greatly appreciate and answers. My specs are as follows.


windows vista home premium SP1 32bit

MOB: Gigabyte GA-EP45-DS3 P45+ICH10 DDR2 1200 1600MHz PCI-E 2.0 SATAII GLA
CPU: Intel Core 2 Duo E8400@3.00ghz (will OC to 4.0 once i find out my problem)
GPU: MSI 4870-512
RAM: Crucial Ballistix Tracer 2G Kit(2x1024M) PC8500 1066MHz DDR2 CL5
PSU: cooler master 650W

I have spent quite a alot off money on this rig and its a fesh new out off the box shouldn't have problems ;(

Well thanks guys in regards..

Thank you for the reply.

I have not made any changes to the MB BIOS all settings are default there.
Vista is fully installed, And it seems to be running okay.
Oh okay really. I thought i would be alright with 2gb of faster ram maybe not
And i am using 8.12 for my Card
I have GPUZ? and it says "Bus interface : PCIE 2.0x16 @ x16 2.0. that should be right i it says 16x?

And as for games CSS can drop to as low as 40-60 fps and my higest would be 200 fps but my mates with worse pcs then me get more.
On crysis warhead it is 12 fps always, unless i look into the sky its about 40
And COD:WAW which i thought would be smooth as, it can get as low as 13 fps highest 40..

Hey, um i got a new monitor because i was using a CRT, so i have a 22 inch it goes up to 1920x1080 but i use 1680x1050 in game.. but also the thing is i have tryied much lower resolutions and there is no change in fps whats so ever. I have looked all over the net and have tried a lot off things i know i can get much more fps then this thanks for the reply.

Only mentioned the memory as a side issue, but if you`re experiencing lag, long load times it takes a while to change users or taks, you`ll know why.
The PCI-E links are fine.
Check Task Manager to see if any programs or tasks are using a lot of CPU time.
Make sure your MB drivers are installed.
Only play in fullscreen, not a window.
Use either Sandra or Memtest to check your RAM is working and up to speed.
You have plugged BOTH power connectors into the HD4870, right?