I was cleaning my computer one day and I ended up with no sound!! I don't know how I managed to do that, but it's been going on for a few months now, my mother is too lazy to call the computer guy, and I can't stand the silence anymore! Someone PLEASE help!!!

remove you sound card from device manager, assuming it worked before next time you reboot windows should install it properly

how do I do that? Where is the device manager?

start/settings/control panel/system click on hardware tab then, in the middle you see device manager, click on the plus sign beside sound, video and game controllers right click and select uninstall on your sound card

one problem - I don't know which one is my sound card. there's Audio Codecs, Legacy Audio Drivers, Legacy Video Capture Devices, Media Control Devices, Unimodem Half-Duplex Audio Device, and Video Codecs

Looks like your sound card isn't there... Unless your modem is the sound card? When you say you were cleaning your PC, do you mean you physically cleaned it with a duster and vacuum or just uninstalled/deleted bits and pieces? If you opened your PC, check that all the cards are fitted correctly. They should fit tightly into their respective slots. If you just uninstalled/deleted stuff, maybe try physically removing your sound card (after shutting down) then restart. Your sound card is the one with green, blue and pink sockets. After a retstart, check to see if any of the devices you listed above is missing. Either way, shut down again and slot the card back in, and restart. Windows should find the card on startup...

if you were cleaning your keyboard , its possible that you without knowing clicked on mute sound. In the bar where the clock is you should have a little emblom of a speaker click on it and untick mute if its ticked off. If this does the trick dont dust your keyboard with the computer on