Note: Someone may say you can release the D disk space through Shrink Volume. You can follow the procedures shown on the picture below to back up data. Step 1: Manually copy the data of the D drive to another partition (select all -> right-click -> copy), or apply the software CloneGo to back up the data of D drive. Suggestions for partitioning a 1TB(1000GB) hard drive in Windows 10/8/7, which allow you to use your computer without C drive full issue and with less disk fragments.
Best Partition Size for 1TB Hard Drive in Windows