Background: At times you may want to uninstall QLA 4.5 Server and reinstall it on the same machine. However, when you try to reinstall it as a service, you get the following error.

This happens due to some leftover registry entries associated with QLA 4.5, which the 4.5 uninstaller couldn't remove. In that case, you can try the following solutions.

Solutions:
The quick way to resolve this issue is, by installing the latest version of QLA Server 4.6. 

However, in case you don't want to install QLA Server 4.6, then you can try the following solution:

1. First, install QLA Server 4.6.

2. Then, uninstall QLA 4.6 using the uninstaller(QLA Server Uninstaller.exe) available under(C:\Program
    Files\Quark\Quark_License_Administrator\_uninstServer).

3. Restart the machine.

4. Install QLA 4.5 as a service.