Why on earth would you install Windows on a workstation machine when you can use Linux (and there's no limitations such as the need to run IIS, etc)?

A wild guess could be that the work needed to be done on that station was windows only or they did not had *nix people on board or that they wanted to see if this was enough ram for Crysis ...

Well it wasn't windows only was it because they just installed Linux in the end

The developer had lots of Windows desktop experience but little Linux desktop experience. We run a mix of Windows, Mac and Linux here, so using Windows shouldn't have been a problem.