new guy dumb to technology, please HELP

Hello everyone,
I'm sorry if this gets long. I have had my Acer Aspire 5315-2077 (160gb hdd, 1.86ghz, 1gb ddr2)for a little over a year. It runs Vista home basic. I bought it mainly to surf the net, get a good webcam so I can keep in contact with my wife (I travel A LOT), and to use as a portable music recording studio. I am very dumb when it comes to technology, however, I would like to know and do a few things. when i go under computer to see how much free space i have on comp its not much but says 7 out of 69.7gb remaining for the c: drive. My d: drive is not even being used and has all the 69gb left. Is there any way i can use that to? can i upgrade the express card 54? I know I use a lot of stuff on my comp but I really would like this one to to its full potential for the studio and webcam. Also, what are some of the best webcams? I had a cheap philips that didnt work out. I'm looking for something with effects (maybe thunderstorms in the background) so i can do music videos as well. I'm sorry if this is not the place for this post, but I really need some help. Thank you in advance

Matt