Shrinking "C" partition in vista

Hi, i have a 120gb hard drive on my relatively new (<2 months) laptop running Vista Buisness.

Atm, i have several partitions:
C- system files for Vista - 58gb ttl, 16gb used, about 40gb free
E- data drive- 35 gb ttl (i want to make this one bigger)
Ubuntu (linux)- 15 gb
Ubuntu (linux) swap- 2gb

Im trying to shrink the C partition down to 20gb, and then either expand the e partition, or delete it and make a new data partition

But Vista won't let me shrink C, ive tried defragging it even, but the "avalible shrink" space is 0 bytes.

The end goal is a a large E drive solely for data. Ubuntu and vista will both be using it- i know how to set this up already.

But the C drive won't shrink!

 

compress the drive using windows compression utilty

 

Could you explain a little more? ATM, im trying to use the built in "Disk management" component of vista.

Why the volume won't shrink, i do not know, I have shrunk it before.

Is the hardrive litterally partitoned off front middle end?

or is it jst a virtual percentage?