Find out if it's the speakers or the PC that's ginving problems. Simply try the speakers on another PC and/or other speakers om this PC.

If you're sure it's the PC, first check Device Manager if it notes any problems. And it won't harm at all to check the settings of the sound software. Something might have been switched to 'mute' by accident.

If none, undo the cleaning either by System Restore or by the undo options of your cleaning software, if those exist. That clearly depends on what you cleaned and how you cleaned it.
If yes, reinstall the drivers.

A repair install of Windows is the next step. A clean install of Windows comes after, and if even that doesnt help it's time to buy a new sound card.