I meant virtual application which let you save applications in USB sticks . and in those cases, u don't need to install REW in your OS. just double click in USB stick and it starts without installing the apps on OS. and when when you close REW , then it doesn't modify window os registry at all...Its kind of hard to understand what your trying to do but the only way to make REW portable is to use a laptop with a soundcard that accepts a proper line in not a mic in. And get your self a Galaxy CM140 SPL meter.