There are 2 ways to move only the OS:
1) Uninstall programs and files from the C: drive and clone the remaining OS to the SSD with a drive cloning tool like Macrium Reflect Free. Not very practical.
http://www.macrium.com/reflectfree.aspx
2) Paragon Hard Disk Mgr. ($49.95) This program can clone only the OS. There are coupons out there to be able to buy it for $15 to $20. Said to work very well. http://www.paragon-software.com/home/hdm-personal/
Yogi