Text and Images messing up

i am using an older HP pavilion w/Intel Celeron 1.70ghz, 256mb ram, Intel 82845G/GL graphics controller. The problem is sometimes when i am on the internet i get text that overlaps other text. it appears something is making them shift. also have the same problem in a program i am using where there are two hand outlines that have click boxes on each fingertip, problem is the click boxes have shifted. program was on another computer and alignment was ok but this is the computer i wanted to use the program on because it was going to be dedicated to that program only. not sure where to start so i will start here. thanks