Solving 0x00000709 error

Sometimes, when trying to set up a newly added printer as the default printer, you are met with a popup alert screaming “Operation could not be completed (error 0x00000709).

Consequently, this error prevents you from setting your current printer as your default printer. In this post, we’ll show how you can fix this error the Windows Registry.

Step 1: Simultaneously Press on Windows Key + R to open the Run Dialogue Window.
Type regedit, when the regedit file is displayed, Right-click on it and select “Run as Administrator” and hit Enter to open the windows registry Window.

Step 2: On the left Pane, you’ll notice the key registry folders. Expand HKEY_CURRENT_USER followed by SOFTWARE

Step 3: Next, navigate to the path outlined below:
Software>Microsoft >Windows NT>Currentversion>Windows. Right-click on Windows folder and select ‘Permissions’

Step 4: A pop-up dialogue box will appear. Scroll down and locate ‘Administrators’ option and assign ‘Full control’ options . Likewise, do the same to the username you used to sign in with and click OK

Back to the Registry Editor. Locate these two files: IsMRUEstablished and LegacyDefaultPrinterMode, delete them. Once done, restart the PC, the problem is solved.

Useful Links: https://www.drivereasy.com/knowledge/fixed-unable-to-setup-default-printer-error-0x00000709-in-windows-7-easily/