Only VirtualBox 4.0.12 run on my Windows 7 Home Premium

[carloabc]

Hi,

My problem:
I can't open VMs with VirtualBox versions differents than 4.0.12 (newer and older). The installation process of a different version of VBox on my PC (after unistalling 4.0.12) runs without problems, and if I try to open VMs just after installation (without restart the PC) I can use them, but after a PC restart I can run VBox but system shows an error trying opening any VMs.
Following the message after installing VBox ver.4.2.0 (not differrent than any other versions):
Failed to open a session for the virtual machine <VM name>.
Failed to load VMMR0.r0 (VERR_LDR_MISMATCH_NATIVE).
Details:
Result Code:
E_FAIL (0x80004005)
Component:
Console
Interface:
IConsole {db7ab4ca-2a3f-4183-9243-c1208da92392}

I don't know if these information are enough.
Thanks for any help.

Carlo

[mpack]

The message indicates that the software has not been properly installed - there is a mix of VirtualBox components of different versions.

You need to uninstall any previous versions, then check the folders and registry to make sure everything has gone. Reboot the host, then install only the version you want - using "Run as adminstrator".