Related link: http://qtparted.sourceforge.net/
When I originally first set up my Windows XP desktop system, I made the C: drive too small. Eight gigabytes was okay at first, but it started to fill up; even though I installed almost all of my applications and personal files on a seperate partition.
I bought a second hard drive and copied over the contents of disk D: onto it. My plan was to wipe the original D: NTFS partition and re-assign the space to C:. The new disk would be re-lettered to D: so my internal application and registry settings would still be intact.
I did almost everything through Computer Management except for the actual re-sizing. For that, I used QTParted running on a Knoppix 4.02 CD. I changed the C: drive size to 30 gigs and rebooted.
Windows noticed the size change, went through a CHKDISK run, and then rebooted without any problems. No files were corrupted, and I saw a noticeable improvement in a few applications with the new size.
There’s always a risk when you change the partition table with a filesystem on it, especially if you try to make that partition smaller. But I don’t see why I have to rely on an external utility in order to do this. If Windows will let me size the partitions for the initial installation, why won’t they provide me a tool to do it once the OS is up and running?