Q: can't open office 2011 in mountain lion

Office for Mac Support

CT providewd a link to the Office for Mac help forum. He did not ask if you are using Office for Mac.

Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work.

Isolating an issue by using another user account

If the problem is still there, try booting into the Safe Mode.  Shut down the computer and then power it back up. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the grey Apple icon and a progress bar appear. The boot up is significantly slower than normal.

Safe Mode

Safe Mode - About

General information.

Isolating issues in Mac OS X

Permissions Troubleshooting

Step by Step to Fix Your Mac

You may have a corrupt installation since it is affecting at least two applications. Try uninstalling and then reinstalling. Below is directions to make sure all files are deleted.

Office 2011 Removal