What's the status of the "Qlikview Webserver" service?
Normally, I run all the Qlikview services as a network service account that has both local Administrator and Qlikview Administrator group membership. As long as you are a member of both groups it shouldn't matter the ID.
Do you see any warning or errors in the Web Server logs? \QlikTech\QvWebServer\Log\....txt
You could also change the QV Web Server port in QEMC > System > Setup > QlikView Web Servers > QVWS > General > Communication > Port. Then test against the new port setting to determine if it's a port 80 issue, or something else.