if the OS is already installed, i suggest to use Bootit-ng (free for what you want) :
Download the demo version of Boot-It NG from
www.terabyteunlimited.com/ then :
As always, it is best to have a backup before doing disk operations.
here the instructions for 2 partitions :
Resize C: to free up some space
Now make the D: partition
More detail :
- download Boot-It and create a bootable CD (or floppy if you have a floppy drive).
- Boot to Boot-It; select CANCEL at the first prompt; then OK. Then click on Partition Work ... you'll see the partition on the disk
Original layout: CCCCCCCCCCCCCCC ( (where the C's represent C: partition)
resize it, to make free space : click resize, put in the size you want the C: to be
New layout 1 : CCCCCCCCCCooooo <--ooo = free space
now select Create Partition to make a D: partition in the free space
done !