Hi, if the computer beeps twice after you start it, the reason could be your mouse or your keyboard. Iether one of them are not working any more or you might have to plug them in firmly behind the computer and then reboot the PC. Good luck !
Is you computer beeping all the time, or just when you turn it on? If it beeps once or twice when you boot then its telling you everything is ok. But if it beeps more than that tells you a piece of hardwares all wrong and you should check your motherboard or something manual for "beep" codes. Also, where does the beep usually come from? A motherboard i can understand beeping, but a monitor or hard drive usually shouldnt beep at all. Or, does the computer tell you whats "beeping"?
BIOS type (AMI, Aware, Phoenix...) or Motherboard vendor/model and sequence of beeps (like 1 long - 2 short beeps, or continuous beep, or repetitive short beep...) this is very important.
Also, I have these questions for you:
Are you able to get to the windows?
Are there any error messages showing up when you turn on the PC (so-called POST messages)?
If the message escapes you before you can read it you can always press "pause/break" button, and the PC will pause.
Also note the BIOS manufacturer.
BIOS (Basic Input Output System) is a program that is performing tests on your PC every time it starts (among other things).
That is called POST (Power-On Self Test). Any error messages during POST are information of what failed the test. Sometimes they can be numbers, hex numbers, messages like "keyboard not connected" or beeps.
The beeps you are hearing is a code. (That is known as beep code)
Every sequence has it's meaning.
For instance AMI BIOS code for "all OK" is 2 short beeps, while AWARD BIOS is 1 short beep.