Copy and paste doesn't check for errors in transfer, isn't very automated, doesn't do backups neatly and moves all the data instead of just the bits which have changed. rsync for the win
Old school for me, I dd | gzip instead then leave the image on a raid. Works well, probably not the quickest approach and you do need to crack out a copy of linux to put it back afterwards
Windows Xp + careful nliting works well as an alternative, especially if you maintain several different copies of windows at one time or frequently change software but want to keep it compact and tidy. An iso with my motherboard drivers, firefox, vlc, cpu-z and hw monitor has saved me a lot of effort but did take quite some time to set up