Hi Abby,
I'm Evett an Independent Adviser, willing to assist you with your issue.
Excelcnv.exe is a legitimate program - Microsoft Office Excel, part of Office programs. However, sometimes this name is used by malicious authors who are trying to infect computers.
We may try to do basic troubleshooting steps provided in the following article How to Remove excelcnv.exe
https://file-intelligence.comodo.com/windows-pr...
Disclaimer: You can see links to non-Microsoft websites. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.
Best regards,
Evett