The UK launch Windows XP on 25 October will be just one event in a $200m worldwide splurge that Microsoft will use to promote its next-generation operating system.

Despite widespread indifference to XP upgrades – typified by the 50 percent of respondents to PC Advisor's online poll who said they won't bother upgrading Office – Microsoft intends to sweep aside consumer resistance with a tsunami-sized marketing campaign.

"Users aren't convinced because we haven't done the convincing yet," said Windows XP product marketing manager Neil Laver. "If we've done our job properly, no one will be in any doubt as to whether XP is the operating system for them."

Microsoft's marketing spend will be further amplified by PC makers looking to cache in on the opportunity for new sales as people with older PCs upgrade.

The precise marketing plans are still under wraps "so as not to lessen the impact," said Laver. But the budget is double that allocated for Windows 95's launch when Microsoft bought the rights to the Rolling Stones song Start Me Up for its TV ad campaign.

When Windows 95 was launched to consumers, branches of PC World stayed open all night to enable eager customers to buy in the first moments of the official launch day. Significant retail activity is planned for the launch of XP, said Laver.

Windows XP will be aimed at both consumers and businesses.