Windows 7 to come in six flavours

Microsoft has defied the clamour to release a single version of Windows 7, by announcing six different SKUs for the next-gen operating system.

The company is copying the Vista blueprint, with a near identical line-up of Windows 7 versions. They are:

Starter Edition: A lightweight version for netbook computers, that will only be capable of running three applications concurrently. It will lack the vast majority of the advanced features, such as Media Center and touchscreen support, but will include the new Taskbar and Home Group feature.

Home Basic: For emerging markets only. Microsoft has, bizarrely, appeared to swap the meaning of Starter and Home Basic. Intended to "access the internet and run basic productivity applications".

Home Premium: The mainstay version that Microsoft will put the majority of its marketing weight behind. Will include Media Center, touchscreen support, full Aero glass graphics, improved media format support and streaming, and the option to easily share files across a home network with the new Libraries feature.

Professional: A business version for home workers and small businesses not operating on a volume licence. Will include features such as advanced network backup and Encrypting File System. However, BitLocker encryption is once again reserved for the Enterprise and Ultimate editions.

Enterprise: For volume licence customers. Will include all the Professional features, plus BitLocker protection - including the new option to encrypt USB flash drives and external hard disks. Will also include DirectAccess, which allows remote workers to securely access a company network without a VPN.

Ultimate: The all-encompassing version of Windows 7, althoughhere's no repeat of Vista's much-maligned Ultimate Extras. Brandedas the "no compromise SKU for tech enthusiasts" it will include every single feature available in Windows 7.

Microsoft says that, unlike Vista, every higher edition SKU will include all the features of lower editions. This wasn't the case in Vista, where Home Premium included Media Center but Business did not.

Microsoft will throw the bulk of its marketing weight behind Home Premium and Professional, with the company telling reporters that it expects 80% of customers to be running on one of those two SKUs.

The news of six different Windows 7 SKUs will come as a disappointment to many, who had been urging Microsoft to release just one all-encompassing version of the operating system.

Beta testers have been working with a version branded "Ultimate", although Microsoft had pleaded with trialists not to read too much into the name.

Pricing details have yet to be announced, but Microsoft will allow PC owners who've skipped Vista to benefit from upgrade pricing on Windows 7.

Windows XP users will have to perform a clean install of Windows 7, however, while Vista users will be able to keep their existing applications and data with an upgrade install.