VirtualBox Critical Error on Startup

[KonAdams]

Hi all,

Very new to this as this is my first post.
I did an upgraded to newer version of VirtualBox and got error message:
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Failed to create the VirtualBox COM object.
The application will now terminate.
Assertion failed: [SUCCEEDED(rc)] at 'D:\tinderbox\win-4.1\src\VBox\Main\src-server\VirtualBoxImpl.cpp' (412) in VirtualBox::init.
COM RC = E_INVALIDARG (0x80070057).
Please contact the product vendor!.
Result Code: E_FAIL (0x80004005)
Component: VirtualBox
Interface: IVirtualBox {c28be65f-1a8f-43b4-81f1-eb60cb516e66}
Callee RC: E_INVALIDARG (0x80070057)
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I have since reinstalled back to version 4.1.12 and got same error message.
All was working well for me prior the upgrade and now cant get it to work at all.
I only use this for testing on my Windows 7 Pro 64bit pc.
I odnt have any Virtual Machines set up at the moment and am questioning why that error message is pointing to my D: as this is my cd rom drive.
Any help would be greatly appreciated.

Thanks in advance.

[mpack]

The error message is not pointing at D:, the message simply indicates which source code line detected the error. D:\Tinderbox is a path on the PC that built the executable.

If you say that you get this error message when launching the GUI, rather than a VM, then the only thing I can think has happened is a botched install. Uninstall VirtualBox completely, then reinstall - this time ensuring that your user account has admin privileges, and be sure to allow it to install any device drivers it wants to install.