Hello mysisterwill1,
Thanks for the question. Unfortunately, Ignition can only save usernames and passwords to allow you to bypass that step later on. You will have to know the information beforehand to be able to save it.
The best thing to do if you don't remember the username of the computer is to look it up. You'll need to be at the host computer to do this. This KB article should help: http://lmine.ws/hKwb2n
Once you have the username, you'll need the password. Assuming you're using the computer, it either doesn't have a password, or you're asked to enter it whenever you reboot the computer. If the first is true, you can set up an access code using these instructions: http://lmine.ws/edDgZK. If the second is true, then you'll want to use that in combination with the username you found earlier when prompted for this information in LogMeIn.
I hope this information helps, but if you need further assistance, please feel free to contact our support staff directly. We're always happy to help with any questions or issues you might have.
https://secure.logmein.com/contactus
Regards,
Kevin Watson
Technical Support Representative
LogMeIn, Inc.
Email: kwatson@logmein.com