If you are syncing with your PC, you have the option in Windows to set your own password. I think this comes up with the add device option in your Windows bluetooth settings. You may need to remove the device in Windows and re-add it to set the password. If I remember correctly, I tried to set it for no password required and I was unable to do it. Delete/Add with password worked for me.
PP is correct that 0000 is usually the password from a device pairing, but like I stated above, I had to set one of my own. I think I tried 0000 and it didn't work because I had not preset it in Windows first.