Ad hoc wireless networking, which lets several Windows computers share a single connection, was one of several networking features Microsoft claims are not available in Windows 7 Starter.
Those features, which include ad hoc networking, internet connection sharing and network bridging, are present in the more expensive, tools-laden editions, such as Home Premium and Professional.
But according to Rafael Rivera, ad hoc networking is present in Starter, albeit hidden.
"On Windows 7 Starter Edition, the 'Set up a wireless ad hoc network' link in the [Set Up a Connection or Network] dialogue is missing," said Rivera in his Within Windows blog.
Rivera, who regularly roots out under-the-cover facts about Microsoft and Windows, most recently made news when he took Microsoft to task for lifting code from an open-source project for the company's Windows 7 USB/DVD Download Tool (WUDT).
After Rivera disclosed the code appropriation, Microsoft yanked WUDT and then later announced it would re-release the tool as open-source.
Last week, however, it postponed the re-release , saying it needed more time to test the revamped WDUT.
Rivera confirmed that ad hoc networking is part of Windows 7 Starter.
"You're licensed to use ad hoc networking ... you're [just] not licensed to use the shortcut in this dialog [in Windows 7 Home Premium]," Rivera said in this blog.
"To access the wizard that this link normally points to, simply Start Menu search for 'adhoc'."
By searching for 'adhoc' in Starter, then launching the executable, netbook users can create an on-the-fly connection for sharing an internet connection.
Rivera expects that Microsoft will close the loophole in a future update, hotfix or service pack.
"I believe it's safe to assume this is an unintentional screw up. Enjoy it while you can, netbook cheapos," he said.
This is not the first time that a hidden networking feature of Windows 7 has been revealed.
In October, a Philadelphia developer found an unfinished feature of Windows 7 that turns any laptop into a wireless access point, allowing other Wi-Fi-enabled devices to share the connection without special software.
The 'Virtual Wi-Fi' feature in Windows 7, which Microsoft at one point touted, was only half-finished, said Alex Gizis, CEO of Nomadio, whose programmers dug up the hotspot-making code.
Virtual Wi-Fi is similar to, but more flexible, than ad hoc networking.
Microsoft did not immediately reply to questions about ad hoc networking in Windows 7 Starter, including whether it will, as Rivera speculated, issue a patch that will completely disable the feature.
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See also: Windows 7 share grows at expense of XP