Just a caution- be sure you are right about your basic facts.
Many laptops come with 2 partitions; the small one contains an OS backup to be used with the Recovery Disk.
Also, if somebody else hasn't mentioned it, both SeaGate & WD Lifeguard have drive maintainance tools that work like Partition Magic.
Active programs don't have to be installed in C: so you could move a couple lesser used gighogs.
Also, you can reset where temp files are created, defrag & compress C: for a little headroom.
Finally- you could consider the price of Partition Magic as a big discount you are getting on the cost of a USB external, and get the drive space you'll need to truly backup your machine, store Google vids, etc. (And the drive will come with the software to re-partition ALL drives.)