I used the boot hiren disk to partition the hark disk. At that time I reduce the capacity of system disk (C) and raise the others.
But in fact, all the programs or softwares that will be installed will be installed in disk C so now I want to resize the C to increase its capacity BUT now I cannot do it, I juct can resize the others not the system disk?
So how can I increase the system disk's capacity ?
Or can I change D disk (its capacity is very large) into C disk (mean after doing that D will be the system disk)? I can do it with which software?
Help me ! thank you!

I've always been partial to Partition Magic, at least on systems up through XP. It allows you to resize all partions, essentially taking space from D and adding to C, moving the files as needed.

Hi, As stated using a free partition magic should do the trick, but , you can change the default install location of most programs when you install them. this will save you space on "C" and may not have to change the size. If you need the space now, uninstall 1 or 2 big programs (like office) from "C" and install them on "D".

Hi again,
To change "D" to your main drive would require a complete reinstall of all your programs from windows on..... Don't go there!!!!