Installing Visual Studio 2010 Beta2 (Express, Professional, Premium or Ultimate SKUs) results in a failed setup.
If the dd_error_*100.txt contains the following:
[11/25/09,09:24:37] VC 9.0 Runtime (x86):  Setup detection logic indicates that this component is NOT installed, but MSI indicates that it IS already installed. This is usually caused by an incompatible previous version being installed on the system. Check in Add Remove Programs and uninstall any previous versions of VC 9.0 Runtime (x86).[11/25/09,09:24:37] VC 9.0 Runtime (x86):  Error: Installation failed for component VC 9.0 Runtime (x86). MSI returned error code 1603