How to create exact harddisk partition while installing windows

You can create exat partion using following:

102400 MB + 500 MB = 102900 MB = Exact 100 GB Partition
51200 = Exact 50 GB Partition
20580 MB = Exact 20 GB Partition
154100 MB = Exact 150 GB Partition
1049000 MB = Exact 1.00 TB Partition