what is pixel shader?how does it effect the performence of pc?can i upgrade my pixel shader?

Answer 1

Pixel Shaders are basically commands that are meant to be run on your 3D card, typically within recent 3D graphic heavy games. This will only affect your PC in the way of being able to play a certain game or not. Pixel Shader requirements are relatively new and will require a 3D video card that is capable of it. To upgrade to use it, you will need a compatible video card.
Below is a list of cards to avoid, as they do not have the Pixel Shader capability. (when it comes to Nvidia Cards anyway)

NVIDIA Riva 128
NVIDIA Riva TNT
NVIDIA Riva TNT2 M64/TNT2/TNT2 Pro/TNT2 Ultra
NVIDIA Vanta
NVIDIA Geforce256 DDR/SDR
NVIDIA Geforce2 GTS/Pro/Ultra/Ti200
NVIDIA Geforce2 MX/MX100/MX200/MX400
NVIDIA Geforce4 MX/MX4000
NVIDIA Quadro
NVIDIA Quadro2 Pro
NVIDIA Quadro NVS
NVIDIA Quadro4 280XGL/380XGL/550XGL
NVIDIA Geforce2 Go
NVIDIA Geforce4 Go
NVIDIA Quadro2 Go
NVIDIA Quadro4 500 Go

Answer 2

Here is a good description of pixel shader:

http://www.nvidia.com/object/feature_pixelshader.html

Extracted form the above link.

"Pixel Shaders create ambiance with materials and surfaces that mimic reality. An infinite number of material effects replace the artificial, computerized look with high-impact organic surfaces. Characters now have facial hair and blemishes, golf balls have dimples, a red chair gains a subtle leather look, and wood exhibits texture and grain. By altering the lighting and surface effects, artists are able to manipulate colors, textures, or shapes and to generate complex, realistic scenes."

Answer 3

from what i know pixel shadower comes with the graphic card and u wud have to upgrade the graphic card to get a more better picture quality.