If files use CD-Rs, DVDRs or FlashDrives.
It's difficult to backup programs and games as many will not let you run them unless they have been installed. For example MS Office. If you backed up all the proper files scattered across your HD and put them on your new install without a proper install (from a CD/DVD), then as you go to start up Word for example you will get an error message saying "Program not installed properly. Please re-install and try again." or something to that effect. Games are much the same way but you can typically install the game like normal, but overwrite the new files with the old ones and end up with all your saved configs and stuff - I used to do it all the time with Call of Duty. Haven't tried it on Battlefield 2 yet...
Good luck.

