port not found

I have an Uno on windowsXP. On step 4 of getting started ...no port for Arduino seen. Tried 2 differnt computers, it will not show. I am a newbie but usually get it, tried my best.

you should try with another arduino... maybe the 8u2 chip is broken.

(this mean the "core", the atmega328, still work and can be reused)

after a few hrs I tried looking in USB devices and found the port. I tried the "blinK' example and it appeared to successfully load, but the TX/Rx lights didnt show any action . Also a pin 13 led ( and one on board) just blink all the time, even when trying everything . Even with it hooked to straight dc without a computer. Could the board be bad ? I want to try everything before returning it. I bought it from Jameco and still have less than 30 days to return it.

ok, you just incapped in the eternal reset bug. nothing too much bad, look around the forum for the solution. i'v solved mine updating the boot-loader with another arduino, but if i'm right there is a trick with the reset (like keep reset button press until you upload the code and... voilĂ , just be sure to use Serial.begin(9600); or other value into setup.)