Microsoft Office for Mac 2011 - upgrade and install problems
I downloaded and installed the Microsoft Office for Mac 2011 Trial Version (which worked fine). 
After my trial was up I upgraded to Office for Mac University 2011, while the apps worked fine the main dictionary disappeared from Word Excel etc so spelling errors were not picked up. When I checked the spelling options the "Hide spelling options" checkbox was ticked and greyed out

I followed the instructions in the post "Dictionary/Spell Checker Issue" post, however when I reinstalled Office for Mac University 2011 (without uninstalling office first) I had a number of errors when opening documents. E.g:
- excel: the file could not be accessed 
- outlook: could not change to that identity an unknown error has occurred in outlook

Obviously I should have removed Office for Mac University 2011 before the new install but this was not stated in the article.  Below are some links on removing and reinstalling  office for Mac 2011. Do not do a "complete removal" unless you want to loose all your identity data (eg outlook emails)

I then removed Office for Mac University 2011 per instructions below and reinstalled. After this my Word Excel and Powerpoint worked fine but my Outlook would not open and I got following outlook errors:
- could not change to that identity an unknown error has occurred in outlook
Identity could not open with this version of Outlook for Mac
 After several installs I found a useful site that resolved problem by providing instructions for upgrading  Office 2011 to Service Pack 2 (SP2), I can't recall the site but to do this you simply open Word Excel or another office app that does not have errors, then click "Help" then "Check for Updates". Once the new update SP2 update had been installed my outlook problems disappeared and I had full access to my Outlook identity, archives and emails



Here are some of the MS Office for Mac Websites:

Office for Mac Support Site:
http://support.microsoft.com/ph/12853/en-us

Office for Mac 2011 official site
http://www.microsoft.com/mac/support 

Office for Mac Outlook
http://mac2.microsoft.com/help/office/14/en-us/outlook/
 
Office for Mac - Trouble Shooting Outlook
http://mac2.microsoft.com/help/office/14/en-us/outlook/category/50f3755e-724b-4057-a87d-88e5483a8762

Instructions for Removing Microsoft Office and its associated files (without loosing User Data)
http://mac2.microsoft.com/help/office/14/en-us/outlook/item/c73b2f17-61ef-45cc-911f-09c8ffcac9cf?category=50f3755e-724b-4057-a87d-88e5483a8762



  1. In the Finder, under Devices, click the hard disk where Microsoft Office for Mac 2011 is installed.

  2. Open the Applications folder, and then drag the Microsoft Office 2011 folder to the Trash.

  3. Close the Applications folder, open the Library folder, and then drag the following files to the Trash.

    • Internet Plug-Ins/SharePointBrowserPlugin.plugin

    • Internet Plug-Ins/SharePointWebKitPlugin.plugin

    • LaunchDaemons/com.microsoft.office.licensing.helper.plist

    • Preferences/com.microsoft.office.licensing.plist

    • PrivilegedHelperTools/com.microsoft.office.licensing.helper

    Note  In Snow Leopard, you also have to delete all Office 2011 receipts in /private/var/db/receipts/. (Snow Leopard moved receipts into this hidden directory, only available by “Go to Folder” in the Finder, or from the command terminal.)
  4. On the Finder menu, click Empty Trash.

  5. Restart your computer.

  6. Install Office for Mac again.


http://mac2.microsoft.com/help/office/14/en-us/outlook/item/c73b2f17-61ef-45cc-911f-09c8ffcac9cf?category=50f3755e-724b-4057-a87d-88e5483a8762

http://support.microsoft.com/kb/2470204


How to completely remove Office for Mac 2011   Article ID: 2398768   - Dont do this unless absolutely necessary as can delete all your identity data and email 
http://support.microsoft.com/kb/2398768