Screen size changes on System start-up

[userzerox]

Hi! My monitor screen size changes every time i start the system! I have to manually use the buttons provided on the monitor to set the the screen size to make it monitor edge fit. I'm using 17" samsung monitor. Maximum screen resolution is 1024x768. I have to usually set the width option manually at the start-up as the edges of the screen wont fit exactly to the monitor edges. How do i fix this ?

System Information
Graphics Card:Intel GMA950(Inbuilt graphics card)
Chipset:Intel945GCPE