That doesn't mean everything will necessarily stay stable. Key areas that could lead to code changes include issues within installation, security, stability, device compatibility, and software installation. Updated builds are being released daily as such tweaks are made.

"We have a lot of engineers changing a very little bit of code," Sinofsky says. "We're being very deliberate with every change we make."

Some aspects of Windows 7 are still under general development, too: Multilanguage support is currently being programmed, and supporting materials -- a new Windows Web site and updated resource kits, for example -- are also being created.

One area just being tested this week is Windows 7's integrated update system. Microsoft is planning to to Windows 7 RC users starting this Tuesday. The empty updates, , will be used to "verify [Microsoft's] ability to deliver and manage updating of Windows 7 in certain real-life scenarios."