Can't install Boot Camp drivers

To start, I own a refurbished 15" Macbook Pro with OSX 10.8.5 on it. The Macbook is a 15" mid 2012 model and I've had it for a little less than a year now. Today I tried to install Windows 7 Ultimate 64-bit via Boot Camp. The install went fine and I can boot into Windows without a hitch, except I can't right click, nor can I hear any audio (among other things). I researched online and realized I need to install the appropriate drivers, so I saved all the drivers that were provided by Boot Camp onto a flash drive and tried that. Windows popped up the error saying "The version of this file is not compatible with the version of Windows you are running..."

I researched that and realized that the version of BC on my Macbook may not be the appropriate one needed for my Macbook model and I found out that I need version 5.1.5621, so I downloaded all of that and tried to install it and sure enough, I get the same error.

What do I do? According to Apple this is the version of BC that I need, yet it won't work, and I have tried at least 4 other versions as well with zero luck (getting the same error every time).

On my old Macbook which had Snow Leopard on it, it was simple as can be, just insert your OS disc and boom all the drivers were installed fine, but since Mountain Lion doesn't come with an install disc, I can't do that.

Can anyone please help me, this is really frustrating especially considering all I am really trying to fix is the audio issue. Right click doesn't bother me since I use an external mouse most of the time. Is there possibly a way to download the audio driver separately? I was trying to do that but can't figure out which one I need.