The Release Candidate 1 version of IE8 now available cannot be installed under the Windows 7 Beta. Reports indicate IE8 RC1 will be made available for IE7 through Windows Update, but at an undeclared time:

"Also unknown is a timetable for delivering an update to people running Windows 7 beta, Microsoft's preview of its next operating system. The company unveiled the public beta Jan. 10.

Because of the timing of Windows 7's beta, its version of IE8 is a "pre-RC," according to James Pratt, a senior product manager for IE. Microsoft will upgrade IE8 in Windows 7 to RC1 via Windows Update, (Jane) Maliouta said, although she did not disclose a timeline. Users will also be able to download IE8 RC1 manually from the company's Web site, she added."