virtualbox.org

This thread is here to help anyone with the same problem. I already fixed it.

Here's the situation:
- I have an Ubuntu host PC with Virtualization enabled
- I am trying to install 64-bit Windows 7
- It is failing with error code 0xc0000225

The solution is surprisingly simple. Just run Virtualbox as root from the terminal, with command "sudo virtualbox".

An issue with this is that the environment variables are not set, which at the first glance causes any themes you might have set to not be used properly. This is the only thing I've noticed so far, and by the way, gksu will not fix this issue.

I hope this helps.

This is really not the way to go. If you want to do it the right way then post the proper information.
Minimal information needed to be able to help