The last Windows upgrade cycle left a long time between drinks. Windows XP hit shelves in October 2001. Then it was more than five years before Windows Vista succeeded it in January 2007.

Now, Microsoft seems ready to step back to its former upgrade pace, which saw it release a revision of Windows every couple of years in pre-XP times.

To wit, the company today announced it will unveil new details about Vista’s successor, codenamed Windows 7, at its WinHEC developer conference November 5 to 7 in LA. At the same time, Microsoft will release Windows 7 code to third-party software developers – a key phase in the development of a new OS that shows Windows 7 is strongly in train.

With many large organisations yet to upgrade from XP, the relatively early emergence of Windows 7 raises the possibility that many will simply skip a generation, ignoring Vista altogether while they wait for the new OS.

If so, they should take a look at history. An apparently near-finished version of Vista was first unveiled in July 2005. But endless last minute tweaks, and niggles from US and EU antitrust agencies, meant the final version took more than 18 further months to emerge.

And Vista’s first service pack – a milestone many companies wait for before they upgrade, since it irons out bugs that bedevil early adopters – was only released in February this year.

This time around, some insiders are saying the reverse pattern will hold true. Windows 7 is officially due in 2010, but Microsoft may actually push the date forward to next year, reacting to Google’s move to make its web browser, Chrome, a de facto Windows of the internet, housing its free, ad-supported Google Gears software (like Chrome, still in beta) which will compete against Microsoft’s Office cash cow.

While Vista is famously hardware-hungry, early, sketchy reports say Windows 7 will run on Vista-capable hardware. Support for a multi-touch touch-screen (similar to that used by the iPhone and Microsoft’s own table-top Surface computer, currently only available in the US) is another of the new features.

With compatible PC hardware, the technology will let a user draw onscreen with their fingers, or touch the screen to quickly flip through a slideshow, or push a map around a display.