The easiest way to partition your drive is through the utility. Disk Management in Windows - Microsoft Support
The system will calculate how much space can be freed. Enter the amount of space to shrink in MB and click .
: If you need to reinstall Windows, your personal data on other partitions remains untouched.
: Keep your OS and applications on one partition (usually C:) and your documents, photos, and videos on another.
Most Windows 7 systems use the Master Boot Record (MBR) style, which supports up to 4 primary partitions and a maximum disk size of 2TB. Newer systems with UEFI may use GUID Partition Table (GPT) , which allows up to 128 partitions and supports disks larger than 2TB.