My computer has 2 internal SATA drives and a USB2 external drive. My c(system+program) and d(data) drives take several hours to back up to the external drive. This may be because d: includes 45Gb of jpg andMP3 files. With normal compression, this weighs in at a 60Gb image file. Back up to the spare internal SATA drive takes only 30 minutes. I propose to image to the internal SATA and then at some convenient point, move the file over to the external USB. This will be a whole lot quicker than going direct to the external drive. Is there any inherent problem or danger with working this way? Any precautions to take?