Q:

I have 21.5GB free. Why won't my MacBook Air 2010 let me use Boot Camp?

I'm trying to install Windows 7 on my MBA, 2010. 
I open up Boot Camp and attempt to use it, but after the first screen it comes up with an error saying it can't install unless theirs 10GB of free disk space. Right now my HDD has 21.5 GB free. Disk Utility won't let me partition my drive either, so a manual install is out of the question.
I need help! My original thoughts were that my disk needed to be defragged to get 10GB of contiguous space. Is this a possibility?

A:

Unfortunately the solution is not a great one.
I had a similar problem on my MacBook a while ago, and the problem is actually due to file fragmentation, however no defrag tool could actually solve the problem. There are various solutions on Google indicating that a defrag does work, but I had no success with any of them.
The problem is related to how the files are spread on the drive, and BootCamp requires a continues 10GB or more of free space on the drive to be able to create the required partition. 
The only way I got around the problem eventually was to format and reinstall the drive. 
My honest advice is to look at using something like VirtualBox which is free, and create a virtual image for Windows. Depending on what you need to do, you can get away with a relatively small image. Windows 7 can run quite happily with only a 1GB of RAM if you don't need Aero. You can also look at paid for options like Parallels or VMWare Fusion
Alternatively, you could look at installing Windows on a secondary drive via USB. The speed won't be great, but if again, depending on what you need it for, it might be a sufficient solution.

