Nasal: I have been having a lot of issues to get to play this game, and it really is frustrating me.. I hope any of you can help me or tell me if you have been experiencing this problem too... So here i go:

When i installed Witcher 2 i was aware that the game was presenting performance problems for most people, so i installed the game, and removed my nvidia drivers and installed 275.27 beta drivers WITHOUT any of the 3D settings, first of all i set my resolution at 1680x1050 (native) and set everything in low with EVERYTHING disabled (of course uber sampling off and SSAO), when i started the game, it was so laggy i had a hard time clicking the sentences in the conversation. I have been trying to fix this issue since i installed the game like 4 or 5 days ago, i have wasted hours, days searching the internet, forums, posts, i have downloaded and installed every 2011 nvidia driver without any of the 3D settings, i have re-installed the game a few times also, i have tried different graphics settings, like lowering the resolution (seems like the only way to get it playable, like 1024x768) i have even patched to 1.3, i got a friend that was presenting the same problem on the same OS as me, and just installed 175.27 beta drivers and got it to work, but NOTHING seems to work for me. I really doubt it is my PC, it is a little old but i get to run Crysis 2 on good settings and i cant even run W2 in low with low resolution ?

My System Specs are:

Intel Core 2 Duo E4500 @ 2.20GHz 2.20 GHz
4,00 GB Memory RAM DDR2 800 Mhz
EVGA nVidia GeForce GT 430 1 GB DDR3
OS: Windows 7 Professional 64-bit

yaleblor: my system specs are only a little better than yours,what i did was install the game to a different 200gig hard drive thats pretty much empty ,my c drives about half full(300gig) . with a 3069mb pagefile onthe c drive and a 9511mb on the d drive (where tw2 is now located) it runs rather smooth, driver wise the 170.61 nvidia drivers seem to work thebest for tw2 for me, the 1.3 patch also gave me a nice boost , also may be you should try a program called gameboost ,theres a free version the turns off unnecessary programs and frees up ram (very convenient ) http://www.iobit.com/
cpu-intel 6320@3ghz
msi 460 1 gb hawk
maxtor 300,200 gb hdds
vista 64bit
6gb ddr2 pc6400

coastie65: Nasal's Processor is a C2D, not a Celeron and the Dual core aspect doesn't help. Not sure if it has HT or not ( which would marginally help ). It could bottleneck the GPU, but not sure as I haven't checked the specs. Would be interested to know what the PSU specs are and barnd of PSU.

cjrgreen: E4500 is an Allendale, not a Conroe; it's a big difference. E6xxx Conroes were 4MB cache, 266 MHz FSB. E4xxx Allendales were 2MB cache, 200 MHz FSB. Whatever you call them, they're no different from Celerons.

Neither are HT. HT went out with the Pentium 4 and wasn't brought back until Nehalem. But any way you look at it, the OP's CPU is low end and under spec, and the GPU is well under spec.

CPUs like the E4500 were used mostly or entirely in commercially-built computers. This means that any upgrade will have to deal with a proprietary motherboard and BIOS, and possibly with a weak power supply.