when i powerup my pc without ram..then there is no beep sound some thimes

[mmmmmmmmm]

when i powerup my pc.there is no display...but the led light blinks..and all the fans are spinning correctly....i thought may a problem with my ram...for that i removed ram from my pc..and i bootenup..but there is no beep sound...i repeat the same problem again...then there was beep sound...indicating that there is no ram...
i dont understand what may be the problem...
some times ..if unfortunately..my pc starts ..then there will be the problem of restarting...
or some times it may run correctly...for hours.......
please ..answre my question ....if any one can.....

 

[Phillip Corcoran]

Test the RAM with memtest86. Download the CD Image and create a CD from it using IMGBurn. Then boot your PC from it.

Memtest86 (bootable ISO): http://www.memtest.org/#downiso

IMGBurn: http://www.filehippo.com/download_imgburn/

memtest86 will run automatically when it loads from the CD, and will not stop until your press <Escape> key.
Any errors will usually be reported within the first three passes so no need to run it beyond that.

If two or more RAM modules are installed, test each one on it's own so you know which one (if any) has the errors.