COM error - Unkown exception - E_FAIL (0x80004005) - problem launching Virtualbox on a Windows 7 Host

[Paul Smith]

Hi,

I used Virtualbox 3.2.12 for a while and all was fine. I then upgraded to 4.0.4 and found that it would not work with some VHD images that I ported over from Virtual PC. The symptom was a non boot and a black screen. Other threads have indicated that there are some problems with VHD images and 4.0.4.

I therefore decided to revert back to 3.2.12 until the issues are sorted and that's when my troubles began. Every time I try to launch Virtualbox I now get an error:

Failed to create the virtualbox COM object. The application will now terminate Unkown exception d:\tinderbox\win-4.0\src\vbox\main\src-server\virtualboximpl.cpp[518] (virtualbox::init)

Result Code: E_FAIL (0x80004005) Component: VirtualBox Interface: IVirtualBox {d2de270c-1d4b-4c9e-843f-bbb9b47269ff}

Okay I thought - a problem with going back to an old release. So I thought I would go "back to the future" to 4.0.4 and use a conversion tool to convert the VHD's to VDI's. Problem is that I am still getting the error above. I tried deleting the files in .virtualbox under my profile (xml and prev files) but this does not help in either release. I also was careful to reboot after each install / uninstall.

[Paul Smith]

I decided to keep trying and deleted the files again in .virtualbox (xml and prev). I then logged off and back on and tried to launch Virtualbox. It worked!!! The key here was the logging off I think. I saw an error in the event viewer telling me that there was a problem with the msiinstaller and environment variables. It said:

Warning EventID 1032 Source: MsiInstaller

An error occured while refreshing environment variables updated during the installation of . Some users logged on to the machine may not see these changes until they log off and then log back on.

This was at the time I installed Vbox so this is what gave me the clue. Its all good now. I simply had to add a new VM and select the existing disks.