backing up using an external drive?

I would like to back up my two internal drives on an external drive. I am wondering if it is possibile to completely copy what is on the internal drives (system files programs, registry etc) to my external so that if my computer were to crash I could simply copy what was on my old computer to the new hard drive(s). My two quetsion are first what is the most efficient way of doing this secondly would I need to "relink" my shortcuts if I kept the same drive letter? Hope this makes sense.

 

Sounds like you would benefit from something like Acronis which makes a true image of your hard drive. You can download it at a very reasonable cost from here http://majorgeeks.com/Acronis_True_Image_Home_2009_d2236.html