Unable to setup Default Printer, error message: 0X00000709 (risolutivo)

http://answers.microsoft.com/

I would suggest you to try the step mentioned below and check if it helps.

Method: Try to change the default printer value in registry key and check if it helps.

Registry Disclaimer: Important this section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: 322756 .

How to back up and restore the registry in Windows:(http://support.microsoft.com/kb/322756/)

a) Click on Start.
b) Type regedit in the start search and click Enter.
c) Move to the location mentioned below.

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows

d) In the right column, you will find key Device, change the value to your Printer name.e) It is of the format for example: "HP LaserJet 4250 PCL6,winspool,Ne03:".

f)  Right click on the value and click on Rename, change it to your printer name.

As it turns out, in my case (and possibly in kflanagan's case as well) I had to set permissions on the keyHKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows

After I gave the user full control on the key, I could set the value on the Device key as stated above.