Upgraded to Windows 8.1, Missing Boot Camp Drivers, OS X Partition not visible, Boot Camp not installed on Windows 8.1 Partition.

I am using a MacBook Pro Retina 15" (Late 20142013).

I had installed Windows 7 via Boot Camp with no problems, but I did not activate Windows 7.

Today I purchased a Windows 8.1 product key and created an install disk using a USB drive. I ran the disk on the Windows 7 Partition and successfully installed Windows 8.1.

However, the microphone and built-in speakers do not function, nor will Windows recognize my graphics card.

To make matters worse, Boot Camp seems to have been uninstalled along with the rest of my programs during the upgrade.

The OS X partition (I am uncertain which version of Yosemite I have) also does not display under the root folder.

I tried to install drivers and support software versions 5.1.5621 and 5.1.5769. However, when I run the "setup.exe" on a USB drive formatted FAT, I get the message, "This version of Boot Camp is not intended for this computer model."

I was a fool and forgot to create a recovery point in Windows before installation, and I can not revert to a pre-Windows 8.1 state.

What are your thoughts on my situation?

How can I properly install my drivers, and which versions should I download?

Is my OS X installation lost/deleted?

How can I reinstall Boot Camp?

EDIT: 2013, not 2014