Do you have the original install floppies? I think there's a repair disk, but can't recall. If there is, Disk First Aid will be on it. If not, it might be on the first install floppy. If you can find First Aid wherever it is, boot the machine from the floppy and run it.
Each time the machine starts it checks the floppy drive for a bootable disk. If it finds one, the machine will start from it rather than from its own system.
First Aid is notoriously weak, however. If it can't fix it and you have the install floppies, you might be able to find the Sound control panel on one of them and copy it to the machine. Then trash the old one.
If you can't find it on the install disks, or if everything on the floppies is compressed so you can't find it (I can't recall but it's likely), put the machine's System Folder inside a new folder, and name the new folder anything, as long as System isn't part of the name. Cabbages is always good.
Then install a new system from the floppies.
Trash the old Sound control and drag the new one from the new system into the old system's Control Panels folder. Then trash the new System Folder so it won't work on the next restart and drag the old one out of Cabbages. Restart the machine then empty the trash of the new system.
Or, after installing the new system, trash the old one in its entirety.
If you don't have Norton Utilities, which would be able to fix your problem so you could avoid all this, try to find a Norton that is compatible with 7.1. Some later versions won't be. If you find one,
never use its File Saver program. It can hose your files.
Edit: I keep thinking of stuff to add. The install floppies probably are System 7.0, so unless the system you're running now is giving you a lot of problems, and if you had to install a new system to fix the Sound control, kill the new system, not the old one.
