[Stephen]

Using the softwares changers is ok. but the best way to change regions is to flash the DVD rom drive making it totally region free then I use DVD genie to erase the windows region code and also to make power dvd region free. DVD genie also works on many other software dvd programs. That way you are asured that you will never be promted that the DVD is from the wrong region.

The USA uses NTSC the UK uses PAL. The regions were setup to restrict the sale of DVDs from other countries as the US get films before we do and same with other countries, it really has nothing to do with the TV frequency, as I have seen a few region 2 DVDs that are in NTSC and the same with region 0.