I know nothing about how computers works but from what I have read I think this is a motherboard problem.

Yesterday my desktop was working fine. It was the first time I had used it for a while because I normally use my laptop but I wanted to play a new game. It worked fine and I played it untill I was done then shut it down as usual.

But, today when I try to boot it up all it does it beep, about once per second, and the moniter stays blank (stays in stand by mode) what could the problem be and how can I fix it?

Hi there and welcome to the site.

Can you tell us;

The make and model number of your PC
Exactly how many beeps and at what exact intervals

The PC was made by my uncle so it doesn't have a make and model number (he said it would be cheaper but it has caused it to have a lot of problems over the years). I'll have a look to see if I can find any manuals or anything about the parts.

The beeps as far as I can tell are continuous and having timed them there's about a 3 second interval between them.

I can't use that because I would need to run it on my desktop (which won't boot up).

I have found sone things but I'm not sure how much information you want.

Motherboard make: Jetway. Model: V4DP

I have the manual so if you need more info let me know.

EDIT: I think all the details can be found here V4DP

Ooops. Ok, that is at least some info.

Have a look at page 18 (2-7) in your manual. It lists probable beeps and their causes...do any of them seem familiar?

Yes.

Beep:
Long beeps in an endless loop
Meaning:
No DRAM install or detected

What does this mean?

It means that your RAM is either;

1) Faulty
2) Slightly un-plugged

How do you feel about opening the PC?