Microsoft has extended a Windows Vista discount programme for small businesses and homes to Europe, following criticism of the operating system's high price.

However, a number of UK users took the opportunity of the announcement - which shaves 10 percent off additional copies of Vista licences - to let Microsoft know that they consider the offer a slap in the face.

Microsoft this week attempted to combat perceptions that Vista is off to a slow sales start by releasing figures it says indicate Vista is selling faster than Windows XP did initially. Microsoft said it has sold 20 million Vista licences, but has not released details of how it came by these numbers. Windows XP sold 17 million copies in its first two and a half months.

European users have been angered by the high price of the OS in the region and the lack of significant discount programmes that are available in the US.

Amidst this atmosphere of rancour, Nick White, a product manager on the Vista launch team, announced "a pretty sweet deal" for Vista with full or upgrade versions of Vista. He said on an official Vista blog that the Additional License programme lets such users buy up to five more licences for a 10 percent discount.

Users can install the extra copies from the original Vista installation discs, White said.

He reminded users that if they don't buy additional licences, Microsoft's anti-piracy software will automatically strip most features from Vista. "This new programme is a handy way to avoid that situation," White wrote.

The programme has been in place for North America since 28 February, and EMEA users will be able to order licences online through the programme starting on Monday, 26 March. The programme is planned to be available for the lifetime of the product.

Some of the blog's readers pointed out that the offer is a poor substitute for the Family Discount, available only in North America, which allows Windows Vista Ultimate to buy two copies of Vista Home Premium for $49.99 (£25).

Another reader said extra copies might actually be cheaper purchased elsewhere than from Microsoft with the discount. "You can easily find Vista discounted by 5 percent to 7 percent at or marked down by about that much at retail stores like Best Buy," the reader wrote. "Ten percent isn't worth it unless you are completely incapable of comparison shopping."