Microsoft claims it is not ripping off its customers in Europe by charging more for European versions Windows 7 than for those produced for the US market.

The company also said that pricing had been unaffected by the legal wranglings with the EU, however it does not explain why European pricing is higher.

In a letter to the Financial Times, Bill Veghte, the senior vice president for the Windows business group, said "nothing about this [case] will mean higher prices for Windows 7 in Europe."

Veghte was responding to an FT story last Friday that noted that because Microsoft had unilaterally decided to strip Internet Explorer 8 (IE8) from Windows 7, users would need "a fuller version of the new software when they upgrade." The newspaper, however, also made it clear that Microsoft was selling that software, dubbed "Full" or "Full Packaged Product" (FPP) to differentiate it from editions labelled "Upgrade," at the lower prices of the latter.

Microsoft has said it will price the full editions of Windows 7E - the "E" stands for "Europe" - at the lower upgrade prices until at least 31 December, 2009. Windows 7E is part of the Microsoft campaign to head off European Union anti-trust regulators, who have charged the company with illegally tying Internet Explorer (IE) to Windows, from mandating even more drastic measures.

Microsoft is making the price concession on Windows 7 because of technical issues involving upgrades from Windows Vista. Microsoft will block customers in the EU from doing "in-place" upgrades, which would leave some version of IE on the machine. So it will not be selling "Upgrade" editions in the market, at least not when Windows 7 launches in late October.

Veghte explained the move in his statement. "We typically offer two Windows versions to retail customers: a full version for use on any computer and an upgrade version - at a lower price - that can only be used on computers that are already licensed for Windows," he said. "In light of recent changes we made to European versions of Window 7, we will not have an upgrade version available in Europe when we release the new operating system." Those Upgrade-labeled editions, however, are high-priced compared with the same versions offered to U.S. users. The "full" version of Windows Professional will cost EU users €285(£173), even though that edition will be priced at the "upgrade" amount. In other words, EU customers will pay twice the US price.

Microsoft has disputed that figure. According to a company spokeswoman,  talk of "doubling" prices was misleading as prices failed to included VAT. She was unable, however, to provide pre-VAT prices. "There is no way to quote you the prices without VAT without misleading people about what they will pay since VAT is always included," the spokeswoman said.

The difference between EU and US. prices, however, are not as dramatic as she claimed. According to Pennsylvania-based Vertex, a software developer that specialises in high-end tax automation for corporations, the average combined sales tax burden in the US - state, local and city sales taxes - was 8.6 percent in 2008.

Veghte, however, also warned that European prices could climb even higher. "In the future we may have an upgrade offering of Windows 7 available in Europe, and at that time we would revert to differential pricing of the full and upgrade versions, as we have in the rest of the world," he said in his statement.

At some point after 31 December - the only date Microsoft has given as a possible end to the lower "Upgrade" pricing - the company could conceivably figure out the technical issues involving "in-place" upgrading Vista, which has a browser, to Windows 7, which won't. With a true "Upgrade" edition available, Microsoft would, Veghte indicated, price the "Full" versions at their higher numbers.

The full version of Windows 7 Professional has been priced at €309, or $433.99 at today's exchange rate, while Home Premium will cost €199.99, or $280.89. Those same editions in the US are priced at $299.99 and $199.99, respectively.

Microsoft did not make an executive available to explain the pricing strategies of Windows 7 or why the same editions cost significantly more in Europe.