In order to create a new user account, you will need to uninstall and reinstall the software. If you use Windows XP or below you can go to Start > Control Panel > Add or Remove Programs. In the Currently installed programs box, click on the e-NGAS program and then click Remove.
If you have Windows Vista or above you need to go to Start > Control Panel > Programs > Programs and Features. Select the e-NGAS application and click on Uninstall.
After that, run AdwCleaner 2-3 times in a row to make sure that there are no leftover rogue registry keys that may contain information about the old account, and install the program again. This way, you will reset the software and you will be able to create a new account.