When i do virtual drive it eats away my C: Hard drive

Hello,

Whenever i make a VHV On windows 7 it and i add some progrmas to that VHD It eats away my C Drive as we'll because my C: Hard drive is really low...and i wanted to use the VHD on it's own i don't want it to lower my C: hard drive. How do VHD without it lowering down my C drive? because i need an extra hard drive as space...and i can't afford a External hard drive now.....Thanks in return for helping :)