OpenGates is a small tool written in C that will "open" the hardware limitation "gates" of Windows installations. All current Windows versions (up to and including Windows 7) are too stupid to boot after the hardware to which the root disk is connected to has changed. This happens for example if you try to boot a raw copy of a Windows installation in a virtual machine like VirtualBox or VMWare or if you try to use your old Windows installation on a new PC. You will certainly end up with a BSOD telling you Windows can't access his boot device (Error code 0x0000007B). It should be possible to solve this by recovering Windows using the original installation medium but as one does not always has it, I wrote OpenGates.