Windows 7, and the upgrade to Windows 8 was as simple as the author stated. I would like to mention that not all the guides I’ve seen deal with snapshots and I appreciated the coverage in this guide, I also found the discussion on Keeping your VM and Your Data Safe to be well written. It is so important to secure the VM or you risk exposure that you’d otherwise not have. Packt has a few great books on web penetration testing and I highly suggest you check those out as well.
I typically use these Machines to do testing on various Operating Systems, this helped me branch away from VM Ware on Linux and get me into the Windows world. I did some testing after I was finished with the guide and found my VM environment to be nicely secured, backtrack found no vulnerabilities and I had rather decent performance with all normal operations considering I don’t have a high end computing device.