Buying a $50 drive duplicator is the best / easiest method of cloning a drive of same size or cloning a smaller drive to a larger drive. *Biggest concern with a drive duplicator is to make sure you have the drives placed into the correct A & B slots so that your not cloning a empty drive overtop of a drive with the system build to it as for drive duplicators perform a bit for bit replication and so it has no problem erasing an important hard drive with the empty one that is full of many 0's and very few 1's and ruin your day.
Windows 7 has a FREE backup image feature, but I havent used it from one drive to another for internal drives yet direct such as if its even possible to split the 2nd drive into 2 partitions and create an image to one partition and then pass that image to another partition on the same drive with this utility. It might not be possible, but I havent tried that. The problem is that the 2nd drive is probably the one that you want to have an exact copy of windows 7 running on and it would just put the image file on this drive. A 3rd drive is likely needed to perform the Windows backup image thats built into 7. I use an external hard drive through USB that is larger than the capacity of the drive to be imaged. I make sure no other data is on this external and then I go through the process. In the end you have an image of Windows 7 on an external drive. You also need to create a bootable Windows 7 repair disc. As for you boot off of the Windows 7 repair disc and then you perform the restore through that pointed at the external which then pushes the image to the internal. You dont want to have both internal drives installed through this process as for having one drive installed only makes it easier to not wipe out the original drive with what could be a bad image if there were any problems with its creation.
If you want to duplicate one drive to another internally without use of a 3rd drive, you could use an image utility like Ghost or Macrium or another clone utility. Not sure if any of the free or trial editions still allow you to clone or not. Biggest thing to pay attention to through the process is to keep track of the Source Drive and Destination Drive. If you get them backwards with some image utilities it will copy an empty hard drive overtop of a drive with the data, wiping out your build!!!
