You can easily change the default volume labels by using the Label parameters ... I'll save some electrons and combine this in one screenshot. This should be easy enough to figure out
LabelSystem
LabelWindows
Label Recovery
#Drive Label of the System Partition
#Default = System
#Alias = LS, LabelS
[Alias('LS','LabelS')]
[string]$LabelSystem = 'System'
#Drive Label of the Windows Partition
#Default = OS
#Alias = LW, LabelW
[Alias('LW','LabelW')]
[string]$LabelWindows = 'OS'
#Drive Label of the Recovery Partition
#Default = Recovery
#Alias = LR, LabelR
[Alias('LR','LabelR')]
[string]$LabelRecovery = 'Recovery'