Ars Technica has a very disturbing report about limitations on Windows Vista upgrades. Fundamentally, if you buy the Windows Vista Upgrade (rather than the full version), you will now be restricted from performing a full, fresh Windows install. Since we consider a fresh Windows install an absolute necessity from time to time (what with security issues, rootkits, etc), the Windows Vista Upgrade product is fundamentally limiting. Given that it requires that you upgrade on top of what might well be a compromised Windows XP install, you’re already starting off badly. Even though you’ll save a few dollars, we think purchasing the Windows Vista Upgrade with this limitation is ultimately a complete waste of money.