PC slow down while installing or copying

dont know if this is normal or not..my specs is
Intel Pentium D 2.66ghz dual core
9600gt
2gb ram
i tried installing games on my friend pc and it ran smooth while installing it.he can even play a game smoothly while installing..the reason i put this on other hardware is because i dont know what the problem is..so if anyone can help it'll be greatly appreciated

What? I don't know what you are asking for... Is your PC free of spyware or other malware? What program(s) are you running for protection?

what i was asking for is a solution to make the pc run smoothly while copying or installing...its free of spyware and i use AVG and Spybot

So your friend's PC doesn't slow down when he is installing another program. What type of Internet provider are you using? Are you using a router with your modem? If so, your router could be slowing things down

streamyx i live in malaysia and i use Prolink wireless G ADSL2+ Modem/router.also the other 2 laptop and a ps3 is sharing the same connection via wi-fi.

So one laptop works and the other on the same wireless router is slow?

no both of the laptop works...sorry theres actually 4 things sharing the same connection 1 computer,2 laptop and a ps3 the 1 that doesnt work is the computer

I think your friend's processor is AMD..