After Installing Inventor 2018 all Excel files are corrupt

[Anonymous]

I am running a windows 10 computer and had Inventor 2017 running just fine. I added an installation of Inventor 2018 to the computer and ever since that moment every time I try to open an excel file it says it is corrupt. I have even tried to open up the excel files on another computer and it say the same thing. What would make excel file get corrupted from installing 2018 and how can it be resolved?

[Mark.Lancaster · Accepted solution]

@Anonymous

Are these excel files related to Inventor?  However, Inventor installation does not impact non-Inventor files.

Update:  Are these files backed up?  Where are they located?  Local or on a network?   Are you sure you were not hit by a virus?

[Anonymous]

The files are all local. No virus was detected. All excel files are corrupt. New files are fine and opening other excel files sent from other computers open fine.