VirtualBox E_OUTOFMEMORY

I've tried running both 4.2.14 and 4.2.16 on Windows Vista Home Premium, SP 2 (64 bit).

Shortly after starting a freshly-installed VirtualBox, I get a

Failed to load the global GUI configuration from . The application will now terminate.

Details say "Callee RC: E_OUTOFMEMORY (0x8007000E)."

The 4.2.14 was running fine at one one point (with 2GB RAM) but stopped (without a change in memory). It would not come back after several reinstalls and starting from a fresh reboot.

On the Vista machine, it's not even getting to the dashboard. The same VM images come up fine on a Windows 7 (64 bit) machine.