Sorry for straying off topic, but why would you install a window 7 on the 80Gb hard drive? Your 500 Gb Caviar blue should be much faster than the 80Gb hard drive due to much higher platter density. You will appreciate this speed especially since windows 7, takes up around 15Gb of space. Normally people would install their OS, programs in their fastest drive and get a slower drive as a storage since storage drive don’t need much speed. I recommend partitioning the 500Gb drive and to install windows 7 on C drive. Then you can use the other partition as a storage as well as + 80Gb drive for storage.
(1) There is no need to reformat anything from an additional drive if you hook it up to a com with main drive that has OS already installed. If there are any other OS installed in the additional drive, the com will ask which OS to boot with during the system start up. Don’t install any 2 OS in the same partition though.
(2) Copy all files in the 80Gb drive to 500Gb drive. As for the program files, you should have have all the set-up files saved in one folder for times like this. Too bad if you deleted the set-up files after installing programs/apps, you may have to start from scratch. After you confirm all your important data is safely transferred to the 500Gb drive, installl the windows 7 on the 80Gb drive. During installation (after you put in the DVD), you will be asked to format the drive.
Actually it’s quite straight forward after you get the hang of it, but I recommend getting help from someone experienced if this is your first time installing OS. As for me, it took me hours and gallons(?) of cold sweat the first time I re-installed my OS.