I know what I did, but I don't know how to fix it
 

I accidentally deleted my router from my computer, thus I can't get on the Internet. Can someone explain to me how to get it back? Thanking in advance.

OK, we need a LOT more info, Windows or Apple product? If windows version?

You should be able to just create a new connection, Windows has a step by step process to do this, you will need the name of your router (SSID), and your password (I hope it is NOT password). I cannot help for Apple products.
Windows:
Get to CONTROL PANEL, select Network, then select setup new connection, and then follow the prompts.

Hope this helps.

by deleting do you mean disconnected? when searching for your router look for a small icon (bars) showing signal strength click on this and it will show all the routers in your area....pick out yours and click on it...you may need a password that was used on initial set up to connect to it though. hope this helps

Did you router come with a disc? My Linskey 2500 had a installation disc, I had to reconnect my router a couple of months ago but that was because Microsoft jammed my computer with Windows 10, even though I said I didn't want it.

I found out that a computer's wireless section has a driver also. I wasn't able to get my printer to work for a couple of months. I went online and got a new HP printer driver downloaded, but that didn't help the priner. Then one day I read with Windows 10 your computer might need a new wireless driver. I found one for my computer, dowloaded the new driver and within a minute my printer was working again.

Sorry, I have Windows. I tried doing what you said and it says I added it but still no Internet.

Sorry, I have Windows. It says I added it but I don't think so because still no Internet.

What is a network security key?