Installation of the Backup Exec Small Business Server license key fails with error
The serial number you entered is for an edition with lower functionality than the one installed. Please manually remove the installed edition serial number if you intend to switch editions.
If there is already a full version core Backup Exec key installed then it will not allow the Small Business Edition license to be entered normally.
1) Within Backup Exec, click the Backup Exec applet (yellow icon circle at the top left of Backup Exec UI) and select the menu "Installation and Licensing".
2) Choose the option "Install Options and Licenses on this Backup Exec Server"
3) On the new UI select "Next" to "add" and "import" serial numbers. Make a copy of the list with the serial numbers.
4) On the same screen, uncheck all of the options for the products installed. This will uninstall the licenses and place Backup Exec into trial mode.
5) Complete the process and Backup Exec services will be restarted. Verify that Backup Exec is now in "Trial Version"
6) After the licenses and products are successfully uninstalled go to the following folder and move the slf files to a temporary folder:
Windows 2003 - C:\Program Files\Common Files\ Symantec Shared\Licenses
Windows 2008 - from C:\Users\All Users\Symantec Shared\Licenses to C:\Program Data\Symantec Shared\LicensesC:\Program Data\Symantec Shared\Licenses
Once the files are moved to a safe location, delete all *.slf files within the folder on the path above.
7) Open Backup Exec and re-run the installation process again. Insert all the licenses again and select all the options/agents for which the licenses have been keyed in.
8) Backup Exec will complete the installation and restart the services.