A customer of mine installed Windows 7 and Office 2007. They migrated there Office from 2003 to 2007. When they try to open an Office document the client asked to authenticate against to the server. With Windows XP and Office 2003 everything works fine. The solution was very simple. They have to run Office 2007 Windows XP compatiblity mode by default.
To accomplish you should put following registry keys to your system:
“C:\Program Files\Microsoft Office\Office12\WINWORD.EXE”=”WINXPSP2″
“C:\Program Files\Microsoft Office\Office12\EXCEL.EXE”=”WINXPSP2″
“C:\Program Files\Microsoft Office\Office12\POWERPNT.EXE”=”WINXPSP2″
Be care with the slashes. If you use a reg file you need to use double slashed \\ instead of one slash \.
If you have no access to the HKLM hive you can use the HKCU hive instead.
This is a known issued. If above solution do not work and for more details about this issued check following blog entry at msdn Office 2007 prompt for user credentials.