Cable not connected

[THE DOC]

Hi guys as the heading this is the error message along with one long beep when i switch on my daughters computer

now ive checked it on a couple of different screens just in case.
Also tried a different graphics card and bee inside looking for something come loose i dont see any thing.

Have i missed something any ideas please people.

 

[THE DOC]

Yes sorry should have said that i did try a different screen with a different lead

ill give the cmos a try ,is it just a case of taking out the battery for a min then restating and putting back in .

 

[THE DOC]

Thanks guys its the memory all right not sure if its one or two sticks ill go test them thanks again