>I'm sure I haven't saved anything on it for ages so don't know how
>it gets full!!
Windows creates all sorts of files "under the covers" without you having to do anything, and these can be quite large.
For example Windows takes a "restore point" every so often and saves these on your hard disk. Try turning OFF system restore, so it deletes all the old restore points, then turn it on again, and you will have only one, saving you space. Also reduce amount of disk space used by System Restore.
Windows also create a hibernation file for when your laptop goes into hibernation and this file is quite large.
If you dont use hibernation you can turn hibernation off and delete the large hibernation file.
http://helpdeskgeek.c...on-file-hiberfil-sys/
Also make sure you empty your recylce bin. When you delete a file it is put in your recycle bin (so still on your hard disk taking up space). Emoty it and it may get you more space.