If you do not have Publisher, the documents must exist before you can delete the reload tasks.
With Publisher there is a separate tab for orphan tasks where you can fix them.
You will need to create documents with the same name as the documents you moved in their original folder locations.
These can be blank QVWs.
Then you can remove the reload tasks against those documents one by one.
Finally once the reload tasks have been deleted, you can delete the QVWs.
If you want to move QVWs to a new folder in future, disable the reload task first, then move the QVW files, then re-enable the reload tasks.