During the install you would have been asked to enter the
username and
password to use (not the
root one). Make sure you don't have your
capslock on and that you are typing the username and password exactly how you typed it during the install stage.
If you decide to start again (it doesn't take an hour to do a reinstall), you don't need to repartition your disk again, just select
Guided - use entire disk. Pay closer attention to how you enter your password,
don't enable the root account when you reboot. If you have followed the guides you should now be able to log into your new Linux Mint install.
See here:
http://www.dedoimedo.com/computers/i...nuxmint_2.html for an example of how to complete the
Who are you? (step 6 of 7) section.