Underscanning issue at PC Boot

Hi all, when my monitor is connected to my HD 5750 via DVI cable i see a black border (about an inch thick) around all corners of my screen until I see windows login screen. I also see this border in safe mode and bios settings screen (the resolution is fine). However there is no such border if I connect it with VGA cable. My card natively support vesa resolution of 1920x1080 and so is the resolution of my LG monitor. I know technically its called under-scanning/scaling but how do I fix it. ATI CCC only helps after windows has booted. I need something that can fix this under scanning issue before winnows has booted. I can't play with monitor settings on digital input. its not a monitor issues as I have tried few diffrent monitors all 1902x1080?

I probably wont care if I was running only windows 7 as that has black background on initial boot, but I am also running hackintosh on my system which has grey background on boot and it looks ugly everytime I boot my system.

Thanks in advance

PS: hackintosh has got nothing to do with the issue.

The AMD drivers are loaded upon boot.
You may want to adjust the underscan and reboot to see if it fixes the problem.

Also your monitor may have a driver that can be installed, that may resolve the issue.

What type of monitor are you using (make, mode number)?

Here is what ComputerHope has to say, scroll down a bit to see the recommendations for LCD's:
Black borders on side of screen.