There are many utilities that are available to help manage disk partitions:
FSUTIL.exe: This is a command line utility that shows the information about the file system and can be used to perform disk related functions.
DFRG.msc and DEFRAG.exe: This is used for defragmentation of the disk drives though personally, I would recommend using Diskkeeper for this task. DFRG.msc is the GUI utility and DEFRAG.exe is a command line utility.
DISKPART.exe: This is a command line utility that can be used to perform disk related functions.
CHKDSK.exe: This utility verifies and repairs FAT or NTFS formatted volumes.
CLEANMGR.exe: This utility is a GUI utility and is used for deleting un-used files.
