There is an update for xDelta, I updated it and I was trying to patch a Clean ROM, then the 'Unhandled exception has occurred in your application' error window appeared with this in it's 'Details': I'm sure it's because the patch comes with the xdeltaUI Mod that you only have to update the xdelta.exe while the UI stays the same. You only have to specify the inputs and outputs. I also have a 64 bit computer and use the xdelta packaged with the download for VW2/BB2. It's basically saying if there is an update for xDelta just update it.
The xDelta will work for both 32bit and 64bit.