Cant connect to wifi but other computer can

[Rolo34]

I moved to my grandparents house 2 days ago and as the title said cant connect to the wifi, but my grandparents laptop can. When fill in the password on my laptop it says its connecting and then it says "network security key mismatch", but when i fill in a random password it doesnt connect at all. I have a HP elitebook windows 7 and a zyxel 2812 modem. Not only my laptop but also iphone and other laptop cant connect. Thank you for your time and help

 

[ktriebol]

Sometimes a letter like a capital J will look like a small j or something like that. The best technique for entering a security key is to use a USB flash drive and copy it from a working computer, then paste it into yours.