you can get a 500Gb (ie nearly 10 times as big ) external drive for about £75 on amazon.
Plugs in to the usb socket - and you would see it as another drive (eg c: for your current hard disk, probably d: for your cd/dvd - so this might be say e.
Really not difficult.
Just beware that you would have the disk die and lose it all - so back up phots particularly to a cd or dvd.