San Francisco - Microsoft on Thursday unveiled pricing for its Windows 7 operating system, which will be available in stores on October 22 to replace the widely reviled Windows Vista.

The world's largest software maker also announced a programme starting Friday through which consumers can pre-order Windows 7 for the next two weeks at discounts of more than 50 per cent. Also Friday, buyers of new computers running Windows Vista will be entitled to a free upgrade once the new operating system is released.

"There is a lot of excitement for Windows 7 in the marketplace today. However, many consumers need a new Windows PC for school, work or home before October 22," said Brad Brooks, corporate vice president, Windows consumer marketing at Microsoft.

"So starting June 26, any customer who buys a PC from a participating computer maker or retailer with Windows Vista Home Premium, Business or Ultimate will also receive an upgrade to the corresponding version of Windows 7 at little or no cost."

Brooks also announced that the Windows 7 prices would be some 10 per cent lower than prices for Windows Vista. Upgrade packages will cost 119 dollars for Windows 7 Home Premium, 199.99 dollars for Windows 7 Professional and 219.99 for Windows 7 Ultimate.

New versions of Windows 7 Home Premium will cost 199.99 dollars, Windows 7 Professional will cost 299.99 dollars and Windows 7 Ultimate will cost 319.99 dollars.

Windows 7 will be available on October 22 in the following 14 languages: English, Spanish, Japanese, German, French, Italian, Dutch, Russian, Polish, Brazilian Portuguese, Korean, Simplified Chinese, Traditional Chinese and Chinese (Hong Kong).

On October 31, a further 21 languages will become available: Turkish, Czech, Portuguese, Hungarian, Swedish, Danish, Norwegian, Finnish, Greek, Ukrainian, Romanian, Arabic, Lithuanian, Bulgarian, Estonian, Slovenian, Hebrew, Thai, Croatian, Serbian Latin and Latvian.(dpa)