The above answers are correct, the floppy drive is essentially a redundant storage device. It holds a relativly miniscule amount of data. Many new computers don't even come with floppies these days.
Just download to your hearts content. If your hard drive is getting too full, then learn how to delete stuff to free up more space, or buy an external hard-drive. You can now buy a 160 Gigabyte drive which plugs into a USB socket for �94. � per Mb, that works out cheaper than buying floppies. i.e it will store the same amount of information as over 11,000 floppy disks!