Windows 7 OEM editions: Windows 7 on the cheap

Last week, £70 would snag you a full version of Windows 7 Home Premium. But this morning that all changed. You're now looking at having to spend up to £150 for a full version of Home Premium, or around £75 for an upgrade-only edition (here's why, should you be interested).

But we've got a loophole for you cheapskates, involving something called Windows 7 OEM editions. It could save you as much as £80, but there are a couple of caveats.

What's OEM software?

A piece of software released to 'original equipment manufacturers', or OEMs for short, is usually identical to the same version sold to consumers in stores. They come without the fancy packaging or manuals, because they're intended to be used by computer makers -- folk like Dell, or your local computer company -- for installation on machines they build.

An OEM version of Windows Vista Home Premium will cost you around £80, but some sites such as Ebuyer offer a free upgrade to Windows 7 Home Premium with these copies of Vista. That means you can buy Windows 7 for around £87, rather than £150.

This is how it works: get new computer, install Windows Vista on new computer, use free Windows 7 disc to upgrade new computer from Vista to Windows 7. That's it.

Things to be aware of

Going OEM is like having unprotected sex -- it's not something to jump into without first knowing the risks. The largest of these risks is that your OEM copy of Windows comes with a licence for use on a single machine (specifically, a single motherboard). You can reinstall it on the same computer in future, but only on that computer. The rule is: new laptop, new copy of Windows.

You may also receive limited customer support. If something goes wrong, the first port of call for someone using an OEM copy of Windows is the person who installed it. That'd be you. So ask yourself: do you know how to fix Windows when it breaks?

The simple rule of thumb is this: if you can build a computer, you're probably safe using OEM software. If not, make sure you're familiar with its limitations before diving in at the deep end.