If you get this message Operation could not be completed(error 0x00000709). Double click the printer name and make sure that the printer is connected to the network when you fail to set your printer as the default one, you’re not alone Many Windows users are reporting this problem as well. But no worries, it’s possible to fix.Here is one of the most effective methods for you to try.
Note: The following screen shots are shown on Windows 7, but the fixes apply to Windows 10 and Windows 8 as well.
IMPORTANT: Modifying the registry in your computer could cause irrecoverable error if the modification is done incorrectly, therefore, it is very important for you to back up your registry first.
1) Click the Start button, then type regedit and press Enter.
If User Account Control comes up, please chose Yes at the prompt.
2) Follow the path HKEY_CURRENT_USER\Software\Microsoft\WindowsNT\CurrentVersion\Windows.
3) Double-click Device. Type in your printer name. (The screen shot here is an example only.)
Click OK to save the change.
Note: If you encounter this sort of error “Cannot edit Device: Error writing the value’s new contents“, please follow the steps below to set the permission of the key.
a) Right-click the Windows key on the left side of the panel and then click Permissions….
b) Tick the box Allow for Full Control and Read, then click Apply and click OK to save the change.
4) Right-click UserSelectDefault and click Rename to rename it as your printer name.
There you go! You should be able to set up your default printer now!