Hidden folders by default & Reinstall of Vista-how to go about?

I own an Apple iPod-Touch. I have purchased the latest iPod-Tuch software update. It is I am told saved at a hidden location in my VISTA computer.
The location c:\users:user name\App Data\Roaming\Apple computer\itunes\Mobile Application

Now,I intend to do a reclean install of my Dell VISTA Os. I will lose the above once the format of my C: takes place. I will not be able to get my purchased software for the ipod-touch.
How should I go about in preserving the "ipod touch App Pack 4A93.ipa" file from this hidden location in my VISTA computer?
Thank you for your help and assistance.
Snow

Hello Snow,

You can unhide that hidden (OPTION TWO, step 2) folder, then just copy the file to where you want for a backup.

Hope this helps,
Shawn