This is available as a free download from Apple.
Step 1: Install the Remote Disc sharing software for Windows 7 and Windows Vista. In all the process should take about two minutes. This feature is built into OS X, but you’ll need to install a small utility to share your Windows 7 disc drive with a Mac.
The Remote Disc feature in OS X allows you to use a DVD drive in another computer on your network as if it were attached to your computer, allowing you to install software on a disc to your MacBook Air.