Step 5: Remove the registry subkeys of the 2007 Microsoft Office system. 1  Locate and then delete the registry subkeys of the 2007 Microsoft Office system if they are present. 2  To do this, follow these steps: 3  For Windows XP and Windows Server 2003, click Start, click Run, type regedit, and then click OK.or those who prefer automatic uninstall, there is a Microsoft Office 2007 Complete Clean Registry Removal Tool available. Step 1: Remove any remaining Windows Installer packages of the 2007 Microsoft Office system. 1  Click Start, click Run, type installer, and then click OK to open %windir%\Installer folder.