I purchased Office Home & Business 2011 step up upgrade online in order to get Outlook added to my Office suite. Excel has the reported toolbar corruption. The forums suggest removing all of office and reload. If I do this, will I loose all my email and contact data?
For the third time in a year and a half I was unable to open Outlook getting a message that my identity needed to be rebuilt. 
The rebuild failed and I had to piece together various methods gleaned from these forums and elsewhere on the net to get a semblance of recovery. 
My question is: What causes this Identity corruption? What can I do to avoid it? 
I have seen many work arounds to fix but nothing to indicate a cause.  
Thanks