Varianta 1:
To renamethe global template file, follow these steps:
Exit all Office programs.
Click Start, click Run, type cmd, and then click OK.
Type the following command, as appropriate for the version of Word that you are running, and then press ENTER:
Word 2002 and Word 2003:
ren %userprofile%\Application Data\Microsoft\Templates\Normal.dot OldNormal.dot
Word 2007 and Word 2010:
ren %userprofile%\Application Data\Microsoft\Templates\Normal.dotm OldNormal.dotm
Type exit, and then press ENTER
When you restart Word, a new global template (Normal.dot) is created that contains the Word default settings.
Sursa: http://support.microsoft.com/kb/822005
Varianta 2:
You should make sure you rename the Normal.dot file to a different name, and you should remove any files from the Startup folder. This is not the end of the process; you also need to make a few changes to the Registry. You may want to protect yourself from potential problems by backing up the Registry first, and then you can accomplish the following steps:
Choose the Run option from the Start menu. This displays the Run dialog box.
In the Open box enter the name regedit.
Click on OK. This starts the Regedit program.
If you are using Word 97, select the HKEY_CURRENT_USER/Software/Microsoft/Office/8.0/Word key.
If you are using Word 2000, select the HKEY_CURRENT_USER/Software/Microsoft/Office/9.0/Word key.
If you are using Word 2002, select the HKEY_CURRENT_USER/Software/Microsoft/Office/10.0/Word key.
If you are using Word 2003, select the HKEY_CURRENT_USER/Software/Microsoft/Office/11.0/Word key.
If you are using Word 2007, select the HKEY_CURRENT_USER/Software/Microsoft/Office/12.0/Word key.
Press the Delete key. You are asked if you want to really delete they key.
Click on Yes. The selected key is deleted.
Close the Registry Editor.
Restart Word. Word has been reset to default settings.
Sursa: http://word.tips.net/T001330_Factory_Default_Settings_for_Word.html