It's quite remarkable how you've managed to get three mistakes into that part of the sentence. The second pic shows clearly there is over 18GB, it's running XP Home and the computer is perfectly adequate for that; indeed, it was sold with that copy of Windows already on it!
I've just noticed, the first pic does say that, hence the comment from KneeOn (thought he must mean free space).
So, why does it say that when the second one states (correctly I think) that the C drive is 9.32GB?
I've barely 200MB left and keep getting low disc space warnings. The clean-up usually just compresses old files, but it can't do that any more. So, is there anything obvious from this screenshot? I have expanded the main 'installer' folder showing part of it on the left. Drivespacio will also...