Many XT and some AT-class computers beep once or twice when booting up normally. If your computer shows standard information on the screen, you do not have a problem. If there is anything wrong, the computer will display a screen error message. If there is no video, check first your computer is turned on and plugged properly. The double beep may be to tell you of parity error in the first 64k of memory. (this is the same as the phoenix BIOS error 1-4-2 describe on Step 5). If your lucky, a memory chip has simply worked itself loose on the motherboard, Reset the chips or the SIMMs or DDRs memory strips; if that doesn't worked, follow the directions for phoenix 1-3-3 of Step 5.