I'm a new user of computer. Why is it the old CPU that we have cannot boot up? It continue to sound tiiiiiiiiiit! Then I can't see anything on the screen. PLease help I am in much need of HELP regarding this matter.

Hi,
If your computer emits a non-stop sound, such as a high pitched "whine" while trying to boot up, then doesn't, you possibly have a major problem.
I would take it to a local computer repair shop (store) and let them determine the problem. Be sure to ask an approx. cost beforehand. I offer this suggestion because you are a new user, and until you become more familiar with a computer, it might not be a good idea of trying to fix the inner workings yourself.
I do wish you the best of luck.

Try to disconect the mouse and keyboard first
The sound is definitely an error it can be with those 2

By cpu do you mean the processor??
How old is the computer
Do you get anything on the monitor?
What color is the light on the monitor(probaby near the power button)(green or orange)?
If you have 2 computers(pc) then try the mouse and keyboard and monitor on each to make sure they all work

Read these steps carefuly before proceeding and post a question if uncertin before continuing or you might break something but you won't if you take care and are careful to put everything back

If you don't get anything then it is probably bad ram
You will have to open the case and find a thin rectangular probably 1 inch wide stick connected to a brown slot with other slots next to it(probably on the top right of the motherboard)
I sugest you rub your hands on the case(the metal part) to discharge static
Then there should be 2 clip like pieces on either end of the stick which you press down on to pop the stick out.
Press on them both at the same time to take the stick out
(if you have 2 then swap the locations just to see that they are positioned correctly)

By cpu do you mean the processor?? Honestly I don't know, it's just that everytime I plug the CPU, there's this whining sound.how old is the computer ? the computer is 3 yrs.olddo you get anything on the monitor? No.
What color is the light on the monitor(probaby near the power button)(green or orange)? Flashing green
If you have 2 computers(pc) then try the mouse and keyboard and monitor on each to make sure they all work. I try all this but it still does work.. Since you already take time to help me, can you please give me some pictures of what I should do, so I might have much more visualization of what I should do.

Thank you very much.