It is now expected that Microsoft will cut the price in Australia during the next few days. In the US, Microsoft will reduce prices for Windows Vista Ultimate to $319 from $399 and cut the price for an "upgrade" version to $219 from $259.
The poor performance of Windows Vista emerged from internal e-mails disclosed in a US court last week.
Microsoft certified Intel's 915 chip set as capable of running Vista, even though the e-mails reveal some Microsoft executives were warning that the chipset wasn't capable of properly displaying Vista's graphics features.
The e-mails, first reported in The Wall Street Journal, emerged in a federal class-action suit by consumers alleging that Microsoft's marketing program for Windows Vista misled them into buying unsuitable PCs. They provide an insight into how Microsoft executives and partners grappled with technical glitches as they prepared the delayed Vista for market.