View all drives with the Get-Volume commandlet:

> get-volume

DriveLetter FriendlyName FileSystemType DriveType HealthStatus OperationalStatus SizeRemaining      Size
----------- ------------ -------------- --------- ------------ ----------------- -------------      ----
                         NTFS           Fixed     Healthy      OK                     84.96 MB    625 MB
D           data         NTFS           Fixed     Healthy      OK                      1.73 TB   1.82 TB
C                        NTFS           Fixed     Healthy      OK                    158.09 GB 237.75 GB

A specific drive:

> get-volume C

DriveLetter FriendlyName FileSystemType DriveType HealthStatus OperationalStatus SizeRemaining      Size
----------- ------------ -------------- --------- ------------ ----------------- -------------      ----
C                        NTFS           Fixed     Healthy      OK                    158.09 GB 237.75 GB