I think the problem here is that you are mixing absolutely positioned DIVs with a variable-width table. I looked at the source code, and I see
position:absolute;
all over the place. But near the bottom, I also see a table that you are using for your menu, with a table-width of 20%.
It looks fine on your laptop because the screen is smaller. Your menu on the left-hand side is set to be 20% of the width of the screen. If you look at your site on a larger monitor (like your desktop), the menu will still take up 20% of the screen, but the content part (and the top logo) will remain fixed in the same position (because that’s the way you set it up). The content will always be xx pixels away from the left side of the screen, regardless of the monitor size. On your desktop, try resizing the browser window, and you will see what I mean.
My suggestion would be to pick one or the other — position everything absolutely, with fixed widths — e.g. the menu is set to exactly xxx pixels wide, and the content is set to exactly yyy pixels wide. Or, use variable widths everywhere — e.g. set the menu width to 20%, and set the content area to 80%.
Hope that helps.