Seems your PC can't find the hard disk. Check if the power cable and the data cable are connected correctly.
If no luck, get the disk out, put it in an external enclosure and see (on another PC) if everything is still on it. If it is, consider to make a backup of everything you don't want to lose to another external disk., before tackling the issue with your PC again.
It's likely the contents of the disk are still fine after what you did. To destroy a disk takes something more than paper towels and a multi-purpose wipe.
Yesterday, my PC kept constantly turning itself off randomly. I would turn it back off only for it to happen a minute or two later.
I conducted a quick Google search and found that overheating was the most likely issue so I proceeded to open up my PC and clean it.
I used a vacuum cleaner, small brush and paper towels but I also used some dettol multi-purpose wipes until I found out with a Google search halfway through that they weren't meant to be used.
Now I have just reconnected all the plugs and cables and turned my PC on but it has a message saying "Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key".
I'm really worried I may have just lost all my data and am really not sure what to do!? I feel like shooting myself in the leg because I was just thinking of backing up my PC a few days ago and didn't get round to it.