GPO tool

Group Policy made searchable

A free ADMX browser or comparison tool for IT administrators. Search policies, find registry keys, and see exactly what each setting writes to the Windows Registry. Or compare two GPO backups to see exactly what has changed between them.

Select a product
  • Select a category.

Do not allow COM port redirection

This policy setting specifies whether to prevent the redirection of data to client COM ports from the remote computer in a Remote Desktop Services session.

You can use this setting to prevent users from redirecting data to COM port peripherals or mapping local COM ports while they are logged on to a Remote Desktop Services session. By default, Remote Desktop Services allows this COM port redirection.

If you enable this policy setting, users cannot redirect server data to the local COM port.

If you disable this policy setting, Remote Desktop Services always allows COM port redirection.

If you do not configure this policy setting, COM port redirection is not specified at the Group Policy level.

Registry Information

VendorMicrosoft
ProductTerminal Server
CategoryRemote Desktop Services › Remote Desktop Session Host › Device and Resource Redirection
Applies toComputer Configuration
Supported onWindows XP
Registry Key[HKLM]SOFTWAREPoliciesMicrosoftWindows NTTerminal Services
Value NamefDisableCcm
TypeREG_DWORD
Enabled value1
Disabled value0

Registry File (.reg)

Windows Registry Editor Version 5.00

; Enable the policy
[HKEY_LOCAL_MACHINESOFTWAREPoliciesMicrosoftWindows NTTerminal Services]
"fDisableCcm"=dword:00000001

; Disable the policy
[HKEY_LOCAL_MACHINESOFTWAREPoliciesMicrosoftWindows NTTerminal Services]
"fDisableCcm"=dword:00000000

PowerShell

# Enable the policy
Set-ItemProperty -Path "HKLM:SOFTWAREPoliciesMicrosoftWindows NTTerminal Services" -Name "fDisableCcm" -Value 1 -Type DWord

# Disable the policy
Set-ItemProperty -Path "HKLM:SOFTWAREPoliciesMicrosoftWindows NTTerminal Services" -Name "fDisableCcm" -Value 0 -Type DWord