Wondering where iTunes stores the iPhone and iPod firmware once it is downloaded. Below is the path for Windows XP and Windows Vista.
This way all you have to do is save it just in case you need to restore the device manually.
By the way if you put the device in restore mode and want to manually point iTunes to the firmware of your choice, simply open itunes, then press and hold down the shift key and press the restore button, this will bring up a window that will allow you to choose where the firmware is located.
Windows XP Path:
C:\Documents and Settings\Your User Name Here\Application Data\Apple Computer\iTunes\iPhone Software Updates\
Windows Vista Path:
C:\Users\Your User Name Here\AppData\Roaming\Apple Computer\iTunes\iPhone Software Updates