Fix NS_E_DUPLICATE_NAME (0XC00D0036) in Windows

Quick answer: Rename your computer to something unique via Settings > System > About > Rename this PC, or run Rename-Computer -NewName "UniqueName" in PowerShell as admin.

This error hits when two machines on the same network share the exact same name. Windows uses the computer name for file sharing, printer discovery, and media streaming. If you've got two PCs called "DESKTOP-ABC123" on the same subnet, neither can use SMB or network discovery properly. I've seen this a ton with folks who clone drives without renaming the PC — or when someone sets up a new laptop and types the same name as their desktop.

The fix is dead simple: change the computer name. Here's how.

Fix: Rename your computer

1. Open Settings – press Win + I.
2. Go to System > About.
3. Click Rename this PC (it's under "Device specifications").
4. Enter a unique name – 15 characters max, no spaces, no hyphens if you're on a domain. Use letters and numbers only. Something like "OFFICE-PC-1" works fine.
5. Click Next, then Restart Now.

PowerShell version (faster):

Rename-Computer -NewName "UNIQUE-NAME" -Restart

Run that in an elevated PowerShell console. Hit Enter, and the machine reboots with the new name.

If you're on a domain: You'll need domain admin rights to change the name. Contact your IT admin, or use the System Properties dialog (sysdm.cpl) and change it there.

Alternative fix (if rename fails)

Sometimes Windows won't let you rename because of cached credentials or a stuck network profile. Try this:

1. Open a command prompt as admin (Win + R, type cmd, press Ctrl + Shift + Enter).
2. Run: netdom renamecomputer %computername% /newname:UNIQUE-NAME
3. If that throws an error about duplicate names, check the workgroup name isn't duplicated too. Run wmic computersystem get domain – if it shows your workgroup name instead of a domain, that's fine. But if two machines have the same workgroup name, that's the problem. Change it in System Properties > Computer Name/Domain Changes > Workgroup.

Prevention tip

Next time you build a new PC or join one to a network, pick a unique name right at setup. I keep a simple spreadsheet of all machines on-site with their names and functions. Saves headaches when you've got 30 laptops in a call center.

Had a client last month whose entire print queue died because two desktops were both named "DESKTOP-USER" after a drive clone. Renamed one, rebooted, printers came back instantly.