I was referring only to the strategy of keeping the OS and the application Programs separate from your data. There are many, many advantages to doing that. Some application programs don't even separate your data into a separate folder (data is mixed right in with program files). This is very stupid. The main idea is that once you have an application program all loaded it does not change much, but your data is constantly changing. Therefore it makes sense to backup your data often, and your application programs much less often, thereby save both time and space (backup media). I hope this makes it clearer.