Loads of issues

[themagichoof]

I'm on an early 2008 Mac Pro trying to install Windows 7.

Bootcamp says the compatibility files are unavailable for download.

The 2nd option to install says it can't find the Windows DVD (I'm using USB via the official Microsoft tool)

I tried holding down the option key to boot directly off the USB stick but it's not showing up there either, but it's fine once inside Mavericks.

I also tried using 3rd party software for transferring the ISO to USB.

I almost just want to take the HD out, put it into a PC, install W7 that way and pop it back in.

 

[saturnotaku]

Neither the things you've tried nor what you want to do are going to work. Perhaps you should try installing from the DVD?

 

[themagichoof]

Why do they even have the bootcamp thing at all then?

 

[xcodeSyn]

Why do they even have the bootcamp thing at all then?

Perhaps you should read the Boot Camp Installation Guide and other related info from this link before starting Windows installation:

If you want to install Windows from a USB flash drive and you have a Windows ISO image, select the option to copy the image to a USB flash drive. If this option isn’t available, your Mac doesn’t support installing Windows from a USB flash drive.

FYI, the bootable USB Windows installer you made from the Microsoft tool won't boot in a Mac, and that's why it didn't work. If you still want to install thru a USB drive, you have to hack the Boot Camp Assistant's Info.plist as explained in this thread. It is much easier to install Windows using a DVD drive in your case as the previous poster suggested.