Hi i have recently bought 3.o ghz processor 512 ddr2 533 mhz transcend ram 160 gb seagate hdd and a 945 gnt intel original chipset i want to know that is this chipset a better opton from 915
My new config
V
it is way better dude ... and also has a GMA 950 compared to the 915's GMA 900 chipset ... GFX accelaration i.e.
A
Don't go for onboard video, buy a standalone graphic card.
won't the onboard video be sufficient for viewing movies and playing normal games like quake 4 nfs u2 or mw not under highest graphics settings but in medium settings
Well the IGP is ok for mivies and for games at low settings....but since u have only 512 MB ram then after sharing 128 MB v-ram it would be =384 MB so u will be losing a lotta ram for that...so get atleast a 6200 or 6600 at minimum and later upgrade it to 7900GT or X1900 etc....or ove to DX 10 ...if u can 
Get a 6200 , even that'll be better than the IGP ...
A
Quake 4 and MW require a geforce 6600GT or higher card to be played even on medium settings.