Need help identifying virus

My grandpa is having problems accessing his pictures, it says that they are not found. I’ve run a scan with avast and avira and it comes up clean. We have no idea if it is malware, but I need to know about what malware messes up jpg’s and other picture and it associated extensions?
I’m just trying to find out the problem here. I can provide information, and I am computer literate, but I just need a list of in the wild stuff that would cause it.

We can not open the pictures in any program, we have tried paint, infranview and windows picture viewer. No luck, I will post pictures of the error

I've run a scan with avast and avira and it comes up clean.
Are you running avast and avira at the same time?

Check your computer for Malware with

Malwarebytes Antimalware http://filehippo.com/download_malwarebytes_anti_malware/
after install click UPDATE and run cuick scan, click on REMOVE SELECTED to quarantine anything found

SUPERAntiSpyware http://filehippo.com/download_superantispyware/
Are cookies really spyware and are they dangerous?
http://www.superantispyware.com/supportfaqdisplay.html?faq=26

If anything is found come back and post the scan logs here