EDIT : ^^^ he got it first
When you uninstall Outlook you need to delete the registry entries as well.
You can default your "Formatting" in the options menu... Don't remember which one it is though.
You can also try running outlook from the run line with the following switches :
You can create a NEW outlook profile and link your old .pst / .ost's to it that way.... That should default your formatting issue.