I have seen this problem on quite a few pcs. When pc boots up initially the system uses the default vga driver (640x480). When windows starts it then loads your selected display resolution eg. from 800x600 up to ?2048x1536? depending on monitor size, definition and the state of your eyesight.It appears that as the resolution increases the monitor's physical settings need to be adjusted to "spread" the picture, usually to the right and down. Ofcourse we all do this automatically, during set up, or (for the richer among us) the system builder will have done it for us. The higher the resolution, the more the adjustment. I think this is probably technically a monitor manufacturing "fault" and is more pronounced the cheaper the monitor, but i may be wrong.
The adjustment, is hardware based, with the effect that when booting, which uses the default dos low res (vga), the image is too far to the left/top and is often distorted.
One or other (low or high res) will need to be distorted, either start up settings or windows settings, or a bit of both. I know my choice!!
If there's a more technical answer, or a way of overcoming this, ("you'll have to degause the matter:anti-matter manifolds captain or she's gonna blow!!") i'd be interested to hear.
Don