In Australia, computer fan Daniel Chan was certified as the first official purchaser of Windows 98.

He received a package autographed by Microsoft Chairman Bill Gates.

Internet correspondent Chris Nuttal reports

Hundreds of consumers did line up outside CompUSA stores nationwide in America for a promotion that began at midnight.

However, they appeared to be drawn mainly by a chance to buy a limited number of $800 computers sold for $98 each.

Evolution not revolution

Bill Gates: hoping his baby repeats earlier success

Windows 98, used on nine out of ten of the world's PCs, went on sale in 40 countries worldwide.

The BBC Business Correspondent Patrick O'Connell in New York said three years ago the product lit a fire under retail sales.

Then nearly 20 million copies were sold in its first four months of release.

This time round things so far appear rather more muted.

Analysts say the $90 system system offers more in evolution than in revolution.

Nonetheless the correspondent said it marks an important step along the road to resolving the whole question of the claims against the power and business practices of the world's largest software company.

Last month US Attorney General Janet Reno filed a landmark anti-trust case that alleged Windows 98 is evidence that Microsoft was using its monopoly in the operating system market to gain control of the crucial Internet browser market.