Maybe you've tried out the beta or the RC for yourself. You know Windows 7 is worth getting – but which version of Windows 7 should you buy? Isn't it crazy how many different versions there are?
Actually no; this time around, the different versions make sense because each new version contains all the features of the versions beneath them, so there are no irritating tradeoffs.
And the choice is really clear. Unless you need to join a network domain at work, use Remote Desktop to connect a work server, take files offline from a server, have some folders automatically encrypted or you want to automatically print to a different printer at two physical locations, buy Windows Home Premium.
Apart from this handful of extra features, plus an advanced backup that only works when it's controlled from a server, Windows 7 Professional only has one really useful tool – and you only need it if you give a lot of presentations. You can plug multiple monitors or a projector into any version of Windows 7; but only Professional (and versions above it), has the options to turn on Presentation Mode and then only on a laptop (you'll find it in the Windows Mobility centre, shortcut Windows-X).
This is the same feature as in Vista; when you're giving a presentation the computer stays on even if you leave it past the time when it would normally go to sleep; notifications, system sounds and the screensaver are temporarily disabled; and you can switch to a specific background image instead of whatever embarrassing picture you usually have up – in case you have to view the desktop to find a file. If you do present a lot, it's very useful, but it proves that only business users need to spend the extra on Professional .
WHICH VERSION? It's Microsoft marketing speak, but every version of Windows 7 really does suit a different market
Ignore Windows 7 Enterprise (it's only for large businesses) and Windows 7 Home Basic (because you can only get that in emerging markets like Brazil). You can't buy Windows 7 Starter Edition, either, but you might get it on a very cheap netbook if the manufacturer wants to keep the price way down by saving on the cost of the Windows licence; according to Microsoft's marketing materials, Starter Edition is aimed at "customers of small notebooks who might otherwise choose Linux".