Problem with pc-arduino duemilanove

Hi everybody,i have a problem with my arduino duemilanove and i must to solve it soon because i need arduino for the school-leaving exam.
When i turn on my arduino or when i push the reset button the red led don"t blink, and when i connect it to my pc the pc doesn't detect the arduino.
I try to replace the atmega328p with a new one, now the red led blink, but the pc still not detect it.
I try with another cable, but nothing :~

First you need to detect what causes the problem

  1. the Arduino
  2. the Cable
  3. the PC

you allready changed the cable. so that is not the problem (The cable works for a printer I assume)
you changed the arduino but that did not solve the problem too.

=> the PC is theproblem. Tell us more about the PC? OS, version service pack etc.

I test it in others pc, with others os, but it still not work, pc not detect arduino.... My pc has win xp sp3, i try in ubuntu and win7 too.

Did you install the drivers? e.g. - http://www.arduino.cc/en/Guide/Windows -