POST PARTITIONING
It’s likely, though, that you’re not going into this from scratch. And that’s OK; Windows’ own Disk Management tool (right-click the “Start” button, and select “Disk Management”) is all too happy to slice up the drives of any living system. Open it up, and you may see that what you thought was a simple drive actually consists of several partitions; we tried it on a laptop we had hanging around— one that had seen itself upgraded from Windows 8 to 8.1 to Windows 10 to the Anniversary Update—and found a host of recovery partitions and other empty space. It might be tempting, seeing this, to ditch this wasted space, but without knowing exactly what’s on each partition, we advise that you tread very carefully.
Find your main partition, or a partition you want to split, in the graphical representation. Right-click it, and select “Shrink partition” to begin the operation of creating some empty space. It’s here that you’ll see just how much you’re allowed to shift; so-called “unmoveable” files put a damper on this in a hurry, but this problem can often be sorted by (temporarily) disabling System Restore or running Disk Cleanup. You can shrink your main partition down to the individual megabyte, but be sure to leave a reasonable amount of space free on your Windows partition in order that it can accommodate system updates and
virtual memory. Once the shrink operation is complete, create your new partition or partitions by right-clicking the now unallocated empty space, selecting “New simple volume,” and allocating your desired amount of space, repeating the process for each new partition you wish to create.