Hi
I suggest that you remove Mcafee it’s not the best security software out there it slows the pc down and causes problems. I suggest that you either use Anti Vir, Avast for free antivirus or for paid ones go for Kaspersky / Nod32.
Also a good anti spyware programme as well like Super Anti Spyware Free Edition.
If the above does not work then please try a reinstall of Office.
Hope this helps,