FIRST!!! create a new folder on your desktop. This will be used to get your files in one easy to find location.
get the XI downloader to back up CoD game profiles. Others , you'll have to google where to find them. Be sure to save custom maps if needed. Put them all in your new folder.
As for pix, shouldn't be any reason to have any format other than jpg unless you have need for others (gif, targa, iff). Use windows search for "JPG" then "pgp" (Start/search/pictues, music,videos). Click the check boxes you need and search. When the results window pops up press ctrl-a to select all, r-click and drag them to your new folder. Might take a while depending on your system. On second thought, you might want to save animated gifs also, so do a search for "gif" and repeat. Also look thru them and delete Windows installed pix or incriminating evidence such as Mals boobs.
Search for music or custom sounds (wav, mp3, ogg, flac). Repeat.
Look at the properties of your new folder for the size. If it's greater than 600mb then divide the files into two or more folders of less than 600mb (cd size is 650, 50mb is a safety factor). Now burn everything to disk.
When you set up your new system, I suggest a separate drive or partition to keep all pix or profile backups safe. It also makes it easier to redo next time.
While not needed, I always run KillDisk on my drives before a reinstall. It overwrites the whole disk. I have seen Windows NOT reinstall but meerly "undelete" the previous Windows files.
I use Gparted to partition my drives. Both KillDisk and GParted have free versions and can be found at majorgeek, filehippo or any of the other free sites. Gparted is Linux based but is straightforward and easy to use.
Good luck!!