When computer switch on it automaticly goes to the SETUP. when exit, a message display "SETUP ENTRY KEY DETECTED" and then boot as usual. i cleaned the keyboard and tried. but the result is same. pls help me on this case.
Thank you.

note pad

well, i can only suggest you try another keyboard to see if that cures it.
what key is the usual one to enter the Setup(BIOS) on your pc? then you know which key to inspect more. Different on different makes, but 99% of computers would be one of:
F1 key, F2 key, F10 key, the Delete key

If it goes to cmos/bios setup when you start it up then most likely the bios is detecting a hardware problem. I've seen that happen when the cpu isn't set up properly.

"Setup Entry Key Detected" probably doesn't refer to the keyboard but rather is a notification that something is amiss and needs to be corrected in setup.

Check the motherboard manual for the exact meaning of the message.

I checked some manuals for D945 and D946 boards and that message wasn't listed. If it was a stuck key you'd think it would go into cmos again after exiting setup. Or you'd get a keyboard error.

Googling the term didn't return anything helpful.