Microsoft's PC emulation application Virtual PC 6.1 is incompatible with Apple's now-shipping Power Mac G5s, Microsoft has confirmed.

Microsoft category development manager home and retail division Sandra Peignaux (who holds special responsibility for the product in Europe) told Macworld: "Currently, Virtual PC 6.1 does not run on the Power Mac G5."

Users attempting to install the application will meet an error dialogue, saying: "This application is not supported by the CPU," she said. Users will then be asked to visit Microsoft's Mac support site, MacTopia, where a Knowledge Base article will soon be made available, explaining the situation. This will be "regularly updated", she said.

Peignaux confirmed the reason for this problem: "Virtual PC relies on a feature of the G3/G4 processors called 'pseudo little-endian mode' for increased performance when emulating a Pentium processor," she said.

Because Power Mac G5 processors do not support this feature, "much of the program will have to be rewritten to work on G5's", Peignaux said. Support for Apple's new Power Macs will be introduced in a future release, she confirmed.

While Peignaux could not comment on a shipping date for the new version of Virtual PC, she said: "When we acquired the product we also hired several excellent engineers from Connectix, with an expertise in the product. Development of the next version of Virtual PC is on track."

She also took pains to stress Microsoft's commitment to Mac: "We are doing everything we can to satisfy the market and ensure all our customers are happy. We are focused on solving this problem and are very committed to the Mac market."

Microsoft acquired Virtual PC from Connectix in February this year. Terms of the deal have not been disclosed.