Weird direct X bug when trying to start gmod

I have been trying to start my gmod, and it says:

http://puu.sh/8yVyI.png

It also links me to this page.
When I install that, it goes fine for a little while until it says:

http://puu.sh/8yVG2.png

It then says installation failed and I have to close the installer.

According to DxDiag, I have Direct X 11.

I am on windows 8.1

Open task manager, go to services tab, and start the CryptSvc/Cryptographic services, then run the DirextX setup.

CryptSvc was already started. I restarted it and ran the install and I got the same results

Edit: I googled it and went to the steam support forum, I had to download a DLL file and place it into my garrysmod folder, thanks for the help!