Most likely either the windows user name was changed after it was set up, or the user name consists of two words with at least one space in between (TI does not like spaces in user names).
Here is the work around:
1. While logged in to your normal Windows user, go to START>CONTROL PANEL>USER ACCOUNTS and create a new user named “Backup” (no quotes); make sure you set it up as an administrator account
2. Create a password for that user
3. Once that is done and that window is closed, then open True Image 10, start the wizard for creating an incremental backup, and when it comes to the window asking for the computername\windowsusername (where you got the “Login information is not correct” error), LEAVE the computer name as-is, delete the windows user, and enter “Backup” as the windows user (no quotes). It should look like this:
computername\Backup
4. Then enter the password you assigned to the “Backup” user when you created that account
5. You should be able to continue past that window now and finish the scheduling of the task
6. Success!