How to reinstall sound device

OK, there are two issues here, The original cause of grief was a HDD too full, so let's look there first. Are you familiar with the use of the Recycle Bin? If not, you should understand that, when you Delete a file you don't need any more, it does NOT leave your hard drive. It is merely moved to the invisible Recycle Bin. Later if you change your mind you can go there and recover it.

To really empty space from old files you don't need, you must manually Empty the Recycle Bin. If you have not done any of this, I suggest you first take a look in there in case there are any lost files you really do want to recover. RIGHT-click on Recycle Bin and choose OPEN. Examine all its files. If you need to look at the contents of a file, just click on it to open it as if it were in any other folder, then close it after. Any you want to recover, just RIGHT-click on it and choose Recover. Once you are finished and convinced that all the junk in the Recycle Bin is of no use, click at the top left on "File ... Empty Recycle Bin" and it will do that. Then close it. Now if you check your drive you should find it has more empty space.

OK, back to the immediate problem about the sound device.I'm not sure exactly what you deleted. Within Control Panel ... System ... Hardware ... Device Manager look for the Sound and Games devices and expand that list. If you right-click on any sound-related devices you can Delete or Remove at least some of them, maybe all. Back out of here and reboot and go immediately into BIOS Setup. Find the place where your audio device hardware is configured - I presume you are using the mobo's built-in device. Disable it, Save and Exit and let Windows boot up to recognize its new status with no sound device.

Now, shut down and reboot again into BIOS setup and re-Enable the sound device. Save and Exit into Windows, and it should detect the new hardware and install the required Drivers. If it does not, you can force this by going back into Device Manager to the Sound and Game controller section, and using the menu commands to tell it to Scan for New Devices.