QlikView 11 and IIS 7, QlikView Webserver won't start

[#1]

After installing QlikView 11 (actually upgrading an existing version 10, which is uninstalled during the installation of version 11) the QlikView Webserver service won't start, which probably causes the Access Point to be loading content forever.

Logging from the Event Viewer: 

Service cannot be started. System.ServiceModel.AddressAlreadyInUseException: HTTP could not register URL http://+:4750/QVWS/Service/. Another application has already registered this URL with HTTP.SYS. ---> System.Net.HttpListenerException: Failed to listen on prefix 'http://+:4750/QVWS/Service/' because it conflicts with an existing registration on the machine.

Any suggestions how to solve this issue? Looks like version 10 was not removed correctly/entirely? Thanks in advance for your support.

[#2 · Accepted solution]

The Webserver service was not properly removed by uninstalling version 10 by means of the QlikView installer of version 11. So we uninstalled the fresh install of version 11 and manually removed all the c:\ProgramData\QlikTech folders. And installed version 11 again.

Next to that we installed windows authentication in IIS and now both issues (QV Webserver and Acces Point loading content forever) were solved.