Install Office 2021, Outlook

Copper Contributor

Hi All,


I am trying to install Office 2021 Professional Pro. Seems to install OK 'till I try to open Outlook. I get message:

old  .ost  file needs to be deleted


Can't find that file no matter which of 50 ways I've tried. Have deleted Office and started all over several times. Microsoft by phone or online is of no help. Others want to charge me hundreds after I spent hundreds on a new mini computer from overseas, cables, Office, etc.




Randall Nichols





1 Reply
You need to uninstall the office completely , not only the program , but also the registry, you can use this Microsoft official tool to remove all office programs and office registries completely:
and by the way, I download and install office 2021 from my own MS account with a product key from, it is working perfectly without any problem