Moving Users folders is not so bad but Programs Files will be nigh on impossible with all the associated registry entries etc. What you are proposing to do is based on good practice - keeping the system drive to a minimum size but I would suggest a variation on what you propose. I would still install all apps to the system drive - there are so many inter-related settings (registry, dll files etc that they really belong together - if subsequently one of the drives became damaged or corrupted then the remaining drive would hold data which did not sync with the other). As far as the User folders are concerned - I would certainly avoid the defaulting to storing data, downloads, pictures, docs etc in there - all data should be kept on a separate drive. I never use all those "My This and My That folders - just encourages bad practice. Using this pattern of op sys and apps on one drive and all user data on another I have kept my system drive (Win 7 64 bit plus a host of apps) down to 18GB.