How do I shrink my Hard drive volume?

[Volcompat321]

I want to partition my hard drive. I have plenty of space, but it wont let me shrink it down 21GB. I have no Idea why!
Anyone help me out?
I want to dual boot Vista and Win7. I need to make a partition about 21 GB or so.
(want to boot Win7 64-bit).
http://i278.photobucket.com/albums/kk115/Volcompat321/volume.png
I want to shrink it 21000mb, about 21gb. but it says I don't have that much space left...? Clearly, I do.
Why is 3704 the highest I can shrink?
How do I disable snapshots and pagefiles?

[amtalx]

Do you have enough free HD space to support shrinking it that much?

[Volcompat321]

I have 130+ GB (says 129, but I also have another partition)

http://i278.photobucket.com/albums/kk115/Volcompat321/Hdd.png

Look at total size before partition
http://i278.photobucket.com/albums/kk115/Volcompat321/volume.png

[amtalx]

Wait...those look like two different drives. The first one is D: and the drive you are trying to shrink is C:.

[Volcompat321]

Well, cause I dual booted Windows 7 and Vista, when I'm in Windows 7 it marks the big one as D(which is Vista) and the 7's current one as C. Weird, but here's another pic to show ya.
I took the pic when I was in Vista so it was C.
Even now, as it marked D, it wont let me.

[Smidge204]

Well if they are the same drive...

129GB free out of 198GB = 69GB used. You can't shrink the partition down to 21GB if you're using 69GB. I may be misunderstanding the situation, though.

It may also be that Vista's Shrink is a piece of shit (However unlikely! ;) ), and it is unable or unwilling to move file fragments that may fall physically outside the desired partition size. Try defragging the drive first and see if that helps.

Failing that, try getting some 'real' partition management software. (Does PartitionMagic work with Vista?)
=Smidge=