Although Microsoft has denied pulling the trigger on Internet Explorer 9 (IE9) upgrade offers, some users have reported that the browser is showing up on their Windows Vista and Windows 7 machines' Windows Update lists.
Several systems at Computerworld and elsewhere have offered the IE9 upgrade as an "Important" item on Windows Update, the default update service for consumers and many small businesses.
On the PatchManagement.org mailing list , Susan Bradley, a blogger who covers Microsoft's Small Business Server and who also writes for the Windows Secrets newsletter, noted that the IE9 offer had appeared in Windows Update.
ZDNet blogger Mary Jo Foley also reported on the early appearance of the IE9 upgrade offers yesterday, citing several sources who had contacted her with the news.
However, Microsoft was adamant that it has not begun to officially offer IE9.
"It isn't being offered yet," a company spokeswoman said Wednesday. "We are throttled to 0% right now."
Instead, users who manually check Windows Update for new updates will see IE9 as an optional important update -- the item is unchecked by default -- that will not download and install automatically. Users must check the item in Windows Update, select OK and finally initiate the download.
"This is how any update works through [Windows Update]," the spokeswoman said.
The Computerworld machines that displayed IE9 in Windows Update as an important-but-optional item did so after staffers manually checked for new updates.
When Microsoft does switch on the IE9 upgrade, the browser will automatically be offered to Vista- and Windows7-powered PCs running IE7 or IE8. Users will see a splash screen that allows them to install the new browser, decline the upgrade or ask that it be delayed.
Windows XP users will not see the IE9 upgrade offer or be allowed to download the browser because IE9 does not work on the still-dominant operating system, an omission that rivals like Mozilla have used to their advantage.
Microsoft has not set a date for the automatic upgrade offer, but said last week that it will begin reaching some users this month, and will have been made available to all users by the end of June.
If that timeline is accurate, IE9's distribution pace will be similar to IE8's in 2009. Two years ago, Microsoft released the final version of IE8 on March 19, and started serving the new browser via Windows Update the third week of April.
Microsoft shipped the final version of IE9 on March 14.
The early appearance of IE9 on Windows Update as an optional download would most concern companies that want to block the new browser. As is its practice, Microsoft has issued a blocking toolkit that corporations can deploy to insure IE9 doesn't make it onto company PCs.
Windows Vista and Windows 7 users who manually check Windows Update will see the IE9 download, but must check the item to retrieve and install it.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is email@example.com .
Read more about browsers in Computerworld's Browsers Topic Center.