During the quarterly earnings conference call with analysts last Thursday, Microsoft said any delay in its new Windows operating system could cost the company upwards of $400 million.

The Redmond company's successor to the Windows XP operating system, Windows Vista, is targeted for release in January 2007, however Microsoft CFO Chris Liddell said the financial impact of a slip in to the second quarter could cost between $200 and $400 million.

He notes that Vista is on track for a November release to businesses and enterprises, however, and sales to the consumer market should begin in November.

A delay in Vista shipments could also have a negative impact on the PC industry. Some experts, such as Merrill Lynch's Richard Farmer, already contend slow PC growth as consumers delay purchases anticipating the new software. Delays could further set back hardware manufacturers.

For Microsoft, a $200 million to $400 million loss in revenues would account for from less to half a percent to just under one percent of Microsoft's estimated total income for the Client Group, the division which sells the operating systems. Microsoft projects an 8 to 10 percent increase for that division in 2007.