"Microsoft made some changes to Windows that prevent the .scf hack from working correctly," said Rafael Rivera in an email reply to questions. Rivera blogs at and along with Paul Thurrott, is the co-author of , a book slated for release next month.

The Rivera referred to was first disclosed in April, and allowed users of Windows 8 Consumer Preview to circumvent the tile-based Start screen and automatically shift to the familiar desktop after logging on.

Well-known ZDNet blogger first reported Rivera's conclusions earlier Monday. She also said other hacks, including some that restore the Start button to Windows 8, have been blocked.

The changes were made by Microsoft before it announced the Windows 8 RTM, or "release to manufacturing," milestone last week. Final copies of Windows 8 Enterprise a day later.

Although previews of Windows 8 could be modified to insert a homemade Start button and with more work, bypass the Start screen at log on, Microsoft has invalidated those work-arounds in the RTM build, said Rivera.