I find that windows updates can take a bit of room, do you use another drive for internet downloads and such? I understand the real estate is an issue on a boot SSD, you can greatly reduce some of that space.
Completely removing system restore will help. Also the annoying UAC can give back quite a bit of space.
More ram would allow for the dismissal of the system cache. I have 4 gigs only, so I moved the cache to another hard drive as I rarely need it.
Even though you told the installer for the webcam driver/software to go to a different drive, some of it goes to the the primary drive anyhow. Drivers for example always are located in the \WINDOWS tree (C:\Windows\SYSTEM32\Drivers for example).