Hello. My name is ***** ***** I will be assisting you today.
In most cases you can leave the OS alone and just make another partition to store files on.
go to start menu --> computer management
right click disk 0 or wherever the OS is stored and choose convert to dynamic disk, then right click on C drive in the same area and choose shrink volume.Then right click in the unallocated space --> new simple volume --> next through the settings
go to start menu --> computer management --> disk management **
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