BitDefender could not delete suspicious files

Question

I Logged-in with an Administrator user. When I scan my Transcend flash memory with my BitDefender Anti-virus, It find 36 virus :

As you see above, I click on Delete Files and then I click on Continue :

After a moment, the above windows appear again! but the options are gone!

I Inevitably click on continue! It emphasize that it can't do anything! why?

Note : Files are not password protected!