virtualbox.org

Hi, i have windows 7 32 bit (my computer supports 64 bit but i accidentaly installed 32 bit) and i installed virtualbox and windows 8.1 64 bit but when i try to boot windows 8.1 host restarts, sometimes it works fine but it often restarts and i often cat boot win 8.1 please help me.

Sorry for my bad English.

In your VM Settings, General, Version, change the Version to 'Windows 8.1 (64-bit)'

I dont have 8.1 option i only have windows 8 option.

By the way sometimes it boots normaly without problems and sometimes it restarts.

Then upgrade to a version of VirtualBox that supports Windows 8.1. You can't expect VirtualBox to support guests that didn't exist at the time of that VBox version.

Thanks i'll try that, but is there any way to install new version of virtualbox without replacing old version or to install new version as portable without replacing old version?

No, I'm afraid you can't have multiple VBox versions installed, nor is there an official "portable" VirtualBox. There is an unofficial one, but that's someone else's fork and as such is not supported here.

Incidentally, you may run into RAM shortage problems trying to run Win8.1-64 on this host.