hp 6470b issue

[corvairbob]

i have the hp probook 6470b  and for some reason when i typing like on this topic here i'm typing away and look up and half of what i typed is not there, then all of a sudden it shows up. or if i make a mistake and backspace i tap the backspace button and nothing  happens and then all of a sudden the curser is way back past where i actually wanted to backspace out.

does anyone happen to know if tis might be a processor issue or maybe memory? i have 8gb of ram in the machine. 

it gets real annoying to be typing stuff and then see the cursor has not moved and then catches up. or to have to backspace to make a correction and it fails to backspace as i tap the key.  i have 25mb of internet speed but it did tis when i have 100mb of internet speed so it is not the internet. it has to be my machine. the wife has the same machine and she has no issue like this.

i changed out the memory about 3 months ago and it still happened. the memory is matched brands and types. i have a fe tabs open but that makes no difference if i have 1 tab or 20 tabs it still does it.

i ran memory tests in windows and during boot up in the bois section for both memory and the cpu and nothing shows up. i even ran them in the long test and still nothing. but something is causing this to happen.  it is annoying so i would like to fix it if i can.  i get it using chrome and firefox so it is not the browsers. it has to be in my machine. if i have to change out the cpu i will but need to know what cpu's are compatible  the machine is stock as far as i know it came with 4gb memory and i put in 8 gb . thanks