How to partition hard disk in Windows 7?

1. Click Start, right click on Computer
2. Click Manage
3. Click Disk Management (on the left)
4. Here you can shrink the C: partition - right click it and select "Shrink Volume"
5. Chose a new size for the C: partition that leave enough room for the new partition
6. In the empty space right click and select "New Simple Volume"
7. Select a size for the new partition

Note: Be careful, re-sizing partitions is risky, always a chance something could go wrong - backup anything important.