as somebody who backed up his data onto an external drive i will give you guys some tips.
drive must be set up with a FAT32 partition, or the PS3 will not 'see it' you can do this under disk management in windows. right click on my computer, select manage and then when the box opens up select disc management. you should see your external drive if it is plugged in and turned on (some enclosures for HDs have a on/off switch if it is powered by a AC cord). you should be able to right click and (only if the drive is empty) remove the partition. then add a new one it will open up the windows partition wizard follow the prompts and set up a partition for FAT32. when done you will have to format then right click again and set it as active. when all this is done you should be able to plug in your drive to the PS3 and it will 'see it' when you access the back up utility. If you back up your data and are only swapping to a larger size when you back up it will back up all your saves, any pics and videos you saved (video you have downloaded from the PSN store) and games that required installs as well. it even saves your 'wallpaper' if you had one. the only time you lose things is if you back up data and recover it to a DIFFERENT PS3. you still get your saves and pics, etc but you will lose the installed game data. you will have to re do any games that required them to be installed before you play them again.
