VMs fail to start after upgrade to v4.2.4

[deesto]

Just got prompted to upgrade my VirtualBox (and extensions) installed on Windows 7 64-bit to v4.2.4 from v4.1.22. No errors were reported during the process, and I was prompted to reboot the machine after installation, which I did. Now, when I try to start any of the existing VMs that worked previously, I get an error dialog:
Cannot access the kernel driver! make sure the module has been loaded successfully.
In the background, I can see another window, which disappears when I click "Abort" on the above dialog:
Creating process for virtual machine "[name]" (GUI/QT) ... (1/2) 0%

The following is a "detailed" message from the final dialog after VM failure:

Code: Select all

Result Code: 
E_FAIL (0x80004005)
Component: 
Machine
Interface: 
IMachine {22781af3-1c96-4126-9edf-67a020e0e858}

Between the time that the VMs were working in 4.1.22, and the upgrade to 4.2.4, the only other possible system upgrade was to Flash, which upgraded itself in the background.

[deesto]

Any thoughts on what might be causing this before I try to downgrade, un/re-install? The VMs are completely unusable in this state.

Thanks.

[Allegro]

I have had the same problem with this upgrade on my Win7 64 bit based system as well, but I got my pre-upgrade virtual machines to work by manually installing the vboxdrv driver located in C:\Program Files\Oracle\VirtualBox\drivers\vboxdrv for a default install. Right click on vboxdrv.inf and select install, then you should be good-to-go.

[deesto]

I have had the same problem with this upgrade on my Win7 64 bit based system as well, but I got my pre-upgrade virtual machines to work by manually installing the vboxdrv driver located in C:\Program Files\Oracle\VirtualBox\drivers\vboxdrv for a default install. Right click on vboxdrv.inf and select install, then you should be good-to-go.

WHEW! Thanks Allegro! Manually re-installing this driver seems to have done the trick. How did you figure this out? Maybe the installed un-installs these drivers during an upgrade without correctly replacing them?

[AnotherLife]

Cannot access the kernel driver! make sure the module has been loaded successfully.

The error clearly indicates a problem with virtualbox's driver.

[deesto]

Cannot access the kernel driver! make sure the module has been loaded successfully.

The error clearly indicates a problem with virtualbox's driver.

Yes, and it turns out that the problem with the driver is that the driver was not installed. I'd like to know why this would happen during an upgrade to a working instance.

[Allegro]

I have had the same problem with this upgrade on my Win7 64 bit based system as well, but I got my pre-upgrade virtual machines to work by manually installing the vboxdrv driver located in C:\Program Files\Oracle\VirtualBox\drivers\vboxdrv for a default install. Right click on vboxdrv.inf and select install, then you should be good-to-go.

WHEW! Thanks Allegro! Manually re-installing this driver seems to have done the trick. How did you figure this out? Maybe the installed un-installs these drivers during an upgrade without correctly replacing them?

I actually had a similar problem with a VirtualBox upgrade about five months ago on the same system. I found the solution then in an online forum and reapplied it in this instance. The installer program apparently installed the updated driver file, since its date stamp is 10/26/2012 (newer than my previous upgrade in September), but I believe it did not install the driver information into the registry, so the manual fix was necessary.