Microsoft has admitted that it simply doesn't know whether it can make enough X-boxes to meet its promised total for the US launch of its console on 8 November.

The firm intends to have at least between 600,000 and 800,000 consoles ready for day one of the launch.

Microsoft is also looking to have shipped 1.5 million units in the US by January, as it begins the long road to catch up with Sony's rival PlayStation 2 console, which has already sold more than 15 million units worldwide.

However, the US games industry is beset by rumours that retailers have been told to stop taking pre-orders as the firm will miss its launch target by some way.

Last month, Microsoft denied reports that an alleged glitch with a key component had delayed production for a number of weeks, but put back its Japanese launch three months to February 2002.

Microsoft has said it won't know day-one quantities until its Mexico plant reaches peak production - a claimed 150,000 consoles a week.

Consoles for X-box's scheduled spring 2002 European launch are being manufactured in Hungary.