This process was a little more difficult than I thought it would be. Of course the hardest part was finding the correct driver. To install your OKIDATA 5100n laser printer on Windows 7 (64bit version) download the English C5100n GDI Driver for Windows XP x64 Edition / Windows Server 2003 x64 Edition. The Windows Vista x64 edition didn't work.
Go here to download the driver. Extract the drivers somewhere and then install your printer.