I’m using Windows 7 (64 bit) and happily had VirtualBox 4.3.12 installed.
With some new work I was doing I upgraded to 4.3.18 and then when I attempted to startup any instance I got the error “E_INVALIDARG (0x80070057)” and nothing would start.
After much Googling and messing about with compatibility startup modes I simply uninstalled and moved back to version 4.3.12 and the program runs ok.
