The only way to say that the drivers don't work is to go into Control Panel and see if there's a yellow exclamation mark next to them to indicate an error. If there's no error, they work.
But maybe you mean "the audio and sound don't work, and they did before I reformatted".
After a reformat nothing works: the hard disk is empty. So the first thing to do is to reinstall the OS to get basic functions working. Then install all necessary drivers to get everything working. My guess is you didn't install all drivers. In that case: just continue with the reinstall plan.
I don't think it's hardware damage.
since getting a virus and having to reformat, my audio and sound drivers wont work.... what do i need to do to get my sound back? ive done all the updates, but i think when i got the virus it damaged my sound card, i think... can anyone help me out please..