You have to buy a special tool called a Key Puller to remove a bad key.Replacing it depends upon whether or not you lost or broke the retainer ring.If it's there you can snap it back in.If lost it or broke it you'll have to buy another.
the missing letter is the letter i
If your keyboard is missing a key, press the key-less spot very lightly when used, or try to place the key back on, or at best get a new keyboard.
The Any key.
Probably your keyboard key is not working. Try to replace that key and try to see if it helps, else you may have to replace your keyboard as the last option...
If the number three key is not working you may have a dead key. There are two solutions to your problem. You can either purchase an external keyboard that has a plug-in USB and use that - or replace the keyboard.
When the keyboard is in the "insert" mode, any key that is struck will replace whatever character was at that point.
You should take your broken key to a key shop. Try going to Canadian tire first. If they can't help you, web search for a key shop in your location and they will be happy to help.
Why the window key in keyboard?
They are on a Standard Keyboard. You must have a different kind if they are not there.F11 & F12 are on a standard keyboard and a Mac keyboard. You are not using a standard keyboard if they are missing.
The lowest key on a standard piano keyboard is the A0 key, which is the first key on the left side of the keyboard.
keyboard
If the "At" key on your keyboard isn't working, first check if the keyboard is properly connected or replace the batteries if it's wireless. Try restarting your computer or testing the keyboard on another device to rule out software issues. Cleaning the key and surrounding area might also help if there’s debris causing the problem. If the issue persists, consider using an external keyboard or replacing the faulty one.