Converting cassette tapes with narration only

Using Windows 10 on a PC: I’ve transferred part of a narration only cassette tape (yes, all my connections are correct and I followed input/record instructions) and the conversation comes back all garbled and at jerky speeds. It sounds like two tracks running over each other, when as far as my old portable cassette recorder went, there was no stereo involved. I’m not a techy; is there something I should be doing to the settings? When I listen to the cassettes on my Player, they sound fine. I need them on my Windows 10 PC so I can access them through my transcribing software to type them out. Can anyone help? Thank you!

the conversation comes back all garbled and at jerky speeds. It sounds like two tracks running over each other,

Like an echo, or like two different tracks/two different recordings?

If it’s an echo, make sure you’ve selected the line-input (or your USB connection or whatever you’re using) as your [u]Recording Device[/u] Do NOT select loopback or Stereo Mix, etc.