which would b beta to get pci or usb wi fi?any1 knw the pro and cons?

For a stationary computer I'd use PCI or PCIe. Faster bus, cheaper hardware, protected inside the case.
If the signal is bad one can always move the antenna somewhere else, using a cable in-between.
(First choice would still be to not use WiFi, but network cable.)

Cheers
Olle

I would use a cable bt my telephone,where im gna connect to is in another room,to much hard work to do,drilling then running cable in the roof.

You could run the cable on the floor, following the walls.
Up to 100m cable should work fine as defined by the Ethernet standards.

Cheers
Olle

I could do that bt im to lazi lol,so wat are the cons of using wifi?it is slower than wired wat other cons r there.thanks

Cons of WiFi vs Cable:
- Price
- Reliability (Many components that can go busted. Electrical interference with connection.)
- Security (Requires proper set-up with WPA2-PSK and a strong password to prevent unauthorised access.)
- Speed (Both nominal and practical. Even with only one computer connected the WiFi will go below nominal speed due to the encryption.)
- Complexity (You'll need a properly set up router just to connect a single computer, whereas with a cable it's a simple plug-and-play.)
- Power consumption. The router use electricity constantly, and Wi-Fi signal transmission use more energy than cable to transfer the same amount of data.
- Safety (We don't really know if/how hazardous the high frequency radiation surrounding us is to the human body. I prefer to use caution in this aspect.)

As you can see; if all you want to connect is a single computer then the labour involved is either
mounting one cable along the floor, or
hooking up a Wi-Fi router to the outgoing line and power, configuring it properly, mounting Wi-Fi card in the computer, configuring that one properly.

The advantages of Wi-Fi are:
Freedom of movement. The hooked up equipment can be moved to other rooms without any fuzz.
Ease of expansion. Attaching more equipment to the router later on is a breeze.

Cheers
Olle