Changes

2) in a near future many PC will have OS on a SSD disk to obtain fast start of the PC. Due to the SSD price C:\ partition will be small 64 to 128 GO. We have to offload from it all that is possible. That may include programs, it is presently possible to install Firefox out of C:\ but in case of bug report the only solution accepted by developers is to put back Firefox in "Program files" directory : this position has to be changed...