Run the following script:
Get-WmiObject -Class Win32_logicaldisk -Filter "DriveType = '3'" | Select-Object -Property DeviceID, DriveType, VolumeName, @{L='FreeSpaceGB';E={"{0:N2}" -f ($_.FreeSpace /1GB)}}, @{L="Capacity";E={"{0:N2}" -f ($_.Size/1GB)}}