Can't log in to my account!?

I have two WordPress sites. The first site was created on my mac laptop. Then when I tried to login to that site on my PC computer, I couldn’t. I tried to reset the password, but it didn’t recognize my username or email.

The second site was created on my PC. Just after I created the site, I tried to login but couldn’t. Again, it didn’t recognize my username or email.

What is going on? Please help!