I purchased freerider more than a year ago, i now am trying to install the full content on a new pc, but cant remember my password, and it says it does not know my email address. I have recieved 3 or 4 updates since the first purchase, and have been using them, but now i dont have the info in my inbox, and i can remember password.

You can request a new download link here:

https://itch.io/support

(It's under "Recover purchases")

You need to use the same email address that you used when you purchased it, it is linked to your account.

If you still doesn't manage to get it sorted, email support@itch.io. They handle all the purchases, I'm sure they will be able to help.