I was having the same issue with "installation failed, check the log file for more information." popup when trying to install the 3-D ActiveX
The log file "InstallLog.txt" (winXP @ C:\document and settings\<user>\Local Settings\Temp\InstallLog.txt) had the following info:
[2007/05/10 04:41:34.140] ApplicationStateManager: Queueing Virtual Earth 3D installer download.
[2007/05/10 04:41:34.156] DownloadManager: Queued 'http://go.microsoft.com/fwlink/ LinkId=85449' for download to 'C:\Program Files\Virtual Earth 3D\VirtualEarth3D.msi'...
[2007/05/10 04:41:34.250] DownloadManager: Beginning data download for 'http://go.microsoft.com/fwlink/ LinkId=85449' to 'C:\Program Files\Virtual Earth 3D\VirtualEarth3D.msi'
[2007/05/10 04:41:34.265] DownloadManager: Download complete for 'http://go.microsoft.com/fwlink/ LinkId=85449' to 'C:\Program Files\Virtual Earth 3D\VirtualEarth3D.msi'
[2007/05/10 04:41:34.281] SystemState: Checking the installation state for Virtual Earth 3D.
[2007/05/10 04:41:34.296] InstallManager: Queueing MSI install of 'C:\Program Files\Virtual Earth 3D\VirtualEarth3D.msi' with paramaters ''...
[2007/05/10 04:41:34.312] InstallManager: Beginning MSI install of 'C:\Program Files\Virtual Earth 3D\VirtualEarth3D.msi' with paramaters ''...
[2007/05/10 04:41:34.328] InstallManager: Initialize
[2007/05/10 04:41:34.468] InstallManager: Terminate
#%^&* [2007/05/10 04:41:34.484] InstallManager: Install of 'C:\Program Files\Virtual Earth 3D\VirtualEarth3D.msi' failed, MsiInstallProduct() returned 1620 (System Error Code: 0 (The operation completed successfully. ))
[2007/05/10 04:41:34.593] ApplicationStateManager: VE3D install failed, exiting.
[2007/05/10 04:41:46.375] ApplicationStateManager: Cleaning up ApplicationStateManager...
[2007/05/10 04:41:46.390] Main Dialog: Shutting Down
[2007/05/10 04:41:46.437] InstallManager: Cleaning up InstallManager...
[2007/05/10 04:41:46.453] DownloadManager: Cleaning up DownloadManager...
[2007/05/10 04:41:46.468] Virtual Earth 3D Installation Manager exiting.
Now I am not sure what the exact details are (line beginning with my insert #%^&* could be a starting point!), anyway, upon checking I found "C:\Program Files\Virtual Earth 3D\VirtualEarth3D.msi" size to be 3KB! so I download it manually, (http://go.microsoft.com/fwlink/ LinkId=85449), installed it, and it's all good.
One thing I will mention is that I am behind a proxy, not sure how relevant that is but might mean something to some geek out there : )
hope this helps
Cheers