Sony VAIO dim screen on Windows 8

I solved my problem!

I figured this out by luck. Here's the outline of steps I followed.

1. Download IntelGraphics_V815101955_VistaWin7.zip (search for it on Google. Here's a possible location.). Or, I uploaded it here.

2. In the zip file, find and extra the folder named '64bit'.

3. Download INDVID-00219009-0042.exe (Video driver update) from Sony's website.

4. Disable the default Microsoft driver and boot into safe mode. Through device manager, manually install the driver in steps 1 & 2 by telling Windows to look for the .inf file at 64bit/Graphics.

5. Reboot (the screen will be dark for the time being). Windows is asking for igfxTray module to be installed. Do so.

6. Now install the driver downloaded in step 3. This should allow the monitor to be bright again.

I'll make an image of my PC now, and reinstall sometime to make sure this procedure works. Will report back when that happens.

I can confirm this solution. Many thanks to user12677 for discovering it. It couldn't have been easy.

My method, generally follow user12677 instructions but no need for safe mode.

1. Download IntelGraphics_V815101955_VistaWin7.zip and INDVID-00219009-0042.exe as described by user12677.
2. Unzip (extract) IntelGraphics_V815101955_VistaWin7.zip. In extracted folder, navigate to 64bit/Graphics folder. Right click on igdlh64.inf file and select Install.
3. Execute INDVID-00219009-0042.exe to install the Sony "undim" driver.
4. Reboot and voila ... done.