Installing Windows 8 Developer Preview isn’t always simple. It was troublesome on a 32-bit machine, but much easier on x64.
Since Win8’s debut at Build last September, VirtualBox supports installing Win8 natively, so you’ll want to download the latest version of VirtualBox to make sure you don’t have problems.
Another good option is VMWare. They have a free product, VMWare Player, that runs well. The only problem is it doesn’t have native Win8 support, but don’t let that get in the way. This blog post, [Guide]Install Windows 8 on VMware Workstation with VMware Tools, has been helpful for me. Here’s the real trick to getting this to work, as explained in the blog post: instead of loading the OS right away, check the option that say’s you’ll load it manually later. Then, in the hardware configuration for New CD, specify the location of the *.iso file.
Of the two VMs, I prefer VMWare because of it’s display, performance, and ease of use. VirtualBox is easier to install because of the native Win8 support, but it seems cumbersome with display resolution messages popping up and window sizing. In contrast, once you get past the VMWare Player install glitch, everything just works perfectly.