I've used Acronis Migrate Easy to transfer one 40gb disk to a brand new 160gb and it worked a treat. All you do is stick both disks in the PC boot into Windows and run the software. After following the instructions it will reboot the PC and copy the entire disk to the new disk. Then all that is left is to replace the old disk with the new disk and continue working. Here's the link
http://www.acronis.com/homecomputing...s/migrateeasy/