I bought an HP (a6720y) desktop the other day with Vista installed.
Here's what my harddrive stats looked like the day I got it....
Here's what it looks like now.....
I've gone from 548.80 GB to 534 GB of free space in just a coupel days.
The thing is that all I've been doing is browsing the internet, playing chess and solitiaire, I deleted some bloatware. Nothing that explains such a sharp drop in HD freespace.
It, may the amount of disk space being used by System Restore. You can use the tutorial below to check and see how much is your MAX disk storage space is, and how to adjust this as needed.