It seems pretty straightforward to backup individual files, such as pictures, saved games, or settings files - just copy them straight over to your 2nd HDD or to an online service like DropBox. However, is there any way to backup entire installations of a program?

For instance, my Firefox directory has a lot of personal customizations and add-ons. I don't want to go through each item and decide to back it up or let it go. So my next option is to copy out the entire directory for backup.

But, if I copy the entire directory back onto the HD after a format, it is not an integrated installation and this seems like it could be troublesome. I would assume Windows cannot detect the directory for uninstallation, or would not let you choose Firefox as your default browser, right? I'm no pro, but this sounds like a bad idea.

So my question is whether there is a good way to preserve all necessary files, while also preserving the full installation process of an application. This is not specific to Firefox - I would like to know how to do this for any application.

Thank you.