1. Stick the 50% of the Company's computer users who weren't doing anything but checking their stocks and buying personal stuff from Amazon and Ebay onto Linux Mint. They won't even notice the difference (except their machines will run a helluva lot faster and be a helluva lot more secure).
2. The other 50% get Win8 with Classic Shell. Make it log directly in to the desktop, and hide all the full-screen apps from them. They'll hardly notice the difference, except all the rounded corners are now squared off, and they get prettier wallpaper choices. And their machines will run a helluva lot faster and be a helluva lot more secure.
3. Problem solved.