Upgrade versions of Vista won't allow clean install

Planning to pick up an Upgrade version of Vista and slam down a clean install on your system? Not so fast. Anyone wanting to wipe their drive and install a new version of Vista will have to pay for the privilege--by purchasing a full version of the oft-delayed OS. Microsoft has announced that Upgrade copies of Vista will only allow an over-install on an existing version of XP--leaving behind all sorts of vestigial remnants that will gunk up your system's inner workings, no doubt. Users wanting to wipe their drives and start fresh will simply have to pony up the dough for the full version. While the company's motivation might seem transparent enough (forcing XP users to buy the full version of Vista), it might be even more sinister than that: Ars Technica's Ken Fisher suggests that the real motivation is to force users into buying a new copy for each successive hardware upgrade.

For more on Vista's dirty trick:
- see this Ars Technica article
- or this Gizmodo article