There are currently 3 different iPhones and 2 different iPads in my household that need updating - from iOS versions 3.x, 4.x, and 5.x. In order to make the transition to iOS version 6.0.1 (current), I first have to back up each device via iTunes. Unfortunately, my meagre 60GB SSD system drive will not suffice. I have decided to use NTFS’ junction function to link directories on separate hard drives. I had to move %APPDATA%\Apple Computer from my system drive to a separate D:\, using cmd.exe:
move "%APPDATA%\Apple Computer" D:\
then issue the following command in cmd.exe (as admin):
mklink /J "%APPDATA%\Apple Computer" "D:\Apple Computer"
For the curious, %APPDATA% contains the full path to the Application Data folder of the logged-in user, e.g., C:\Users\ootput\AppData\Roaming