Vista OS reinstall inquiry

My system had been acting up and so I decided to reinstall the OS. When I get to the partition screen it lists only 1 partition at 465GB, but I have a 500 GB hard drive. This was NOT the way it was the last time I reinstalled the OS. Then when I look at the drive list it lists Drive X, which has a bunch of programs listed, including some I do not remember being there such as Panther and whatnot. Is this normal or is there something fishy going on please? I am quite nervous about any possible security breaches, and I notice that after completing the reinstall there are now a LOT of hidden plug and play devices, which are making me even more nervous!

Just to add-  I am not very techno-savvy, but just want to know if this sounds like bad news or really just normal operation and I am being overly paranoid! :)

Thank you!