I installed Postal today off of GOG.com and it has worked fine, up until the library on Tuesday. When i load the library, the load bar fills up, then the game crashes. It gives me an error saying:

"If you don't have DirectX 8.1b or later installed then please install it now. Otherwise, check the Postal 2 Tech Support site for more information."

I have the latest version of directx installed, so the error isn't correct.

So i went searching a bit and found this put up by the Running With Scissors team.

http://www.shacknews.com/file/3035/postal-2-patch-1337

It says in the bug fixes:
"triggered a bug in the DirectX 8.1 runtime" crash fixed on most machines.

But for some reason the patch cant find the right folder. Has anyone else tried this before?

That patch is older then the version you are using so forget that, I'm almost sure the compatibility fix works for this issue infact,

Try right clicking the .exe or shortcut and running it under compatibility for Windows SP2.