Hey i got a problem. Everytime i start my computer the Screen wont come on, it stays totally black, I tried touching themouse or keyboard to activate it but its not working

Help plz

here is a couple of things i would try.
double check the vga cable is connected firmly.
also check the monitor is on.(sounds silly i know).
double check the power lead to the monitor.
is there any lights at all on your monitor.
try another monitor.
does your pc sound like it is booting normally ie the same beeps and noises you used to get.
as another resort you could try and reseat your graphics card, or try another one.
and double check to see that your memory is seated correctly and possibly try another stick.
i am certain someone else on this forum will have some more suggestions if the above does not work for you.
i hope that helps you
post back with full specs

What's the history behind the problem?

Is it a new build?
Did it just one day quit working correctly?
Did you make any changes to the pc prior to the problem starting?