I don't think this issue is directly related to this version as I have tried a few others, but the issue occurs when attempting to install.
After selecting the default compontents and default directory (C:\Program Files\Oracle\VirtualBox) and proceeding with the installation, it appears that the setup dialog box is on "Evaluating launch conditions" and then pops up an error message:
"This application only runs on 32-bit Windows systems. Please install the 64-bit version of Oracle VM VirtualBox 4.2.4"?
First, it would seem from searching that both 32bit and 64bit installations are in this Windows install exe (or at least they should be). I'm not sure why it is detecting able to detect my 64bit system and then attempt to install the 32bit version with the error.
Second, the error message appears to be for the 4.2.4 version, while I have the 4.3.8 installation executable.
I'm not sure what may have happened. Is it possible that I have old files from a previous 4.2.4 installation that need to be deleted? Is there a way I can be sure that all virtual box profile settings and app data has been deleted/removed and then attempt to reinstall?
My home directory is mapped onto a NFS and I am in the process of transitioning from 32bit to 64bit, so this may be playing some part of the issue.