Hm, I think what the OP wanted was something like lshw-gui (or, on second read, maybe not).
Anyway, if you open the terminal and enter 'sudo apt-get install lshw-gui' I think you'll get a more complete picture. (Once you run the app, at least.) You'll need to try something else to see how full your partitions are - though partition managers work for that end, the chance for a regrettable incident is... not my cup o' tea. I also see something in my mintMenu called Device Manager. Pick yer poison!