As a user of Linux, I had the same shortcoming, which I solved by installing virtualbox. Virtualbox, developed by Oracle, is a free piece of software that allows you to run an operating system inside another operating system. For example, I run Windows XP inside my Linux installation for the purpose of running GMATprep, etc.
You can download virtualbox for Mac OSX or you can use Bootcamp to run Windows natively.. your call. Somewhat complex but not terribly difficult. Depending on your needs, it might just make sense to drag out your old PC.
You will need a Windows installation CD/DVD though.