Faulty Wireless Keyboard: Typed letters are different

Wireless keyboard failure? When I turned on my computer and start to do my encoding stuff, I noticed that the letters showed up was different from what I'm coding. Example: I press letter A but the letter showed up was C. My keyboard is crazy. I cannot continue my encoding. And when I press enter button it’s deleting the word.
What should I do? I'm using a wireless keyboard but the battery of my keyboard is new. I'm so curious why my keyboard is like that. How will I fix this problem? Please help me to solve this problem because I will not able to finish my encoding of files. Thanks!
