Unfortunately, the application doesn't have a password reset/recovery feature. The only solution to reset the password is 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 DVSS4 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 DVSS4 application and click Uninstall.
After that, run a registry cleaner to make sure that there are no leftover rogue registry keys that can contain your account information and download and install the application again.