I just had the same problem with a customer. She had installed a Free Version, but couldn't enter it due to password protection. So I just booted the PC into Safe Mode (with Remote Control), turned off the password function in the Free version. Then deleted the Free version with the uninstall tool. Booted back to normal mode and installed the Internet Security version. Then after rebooting for the AIS install I try to check the license information and then the password protection screen comes up again. On a clean install! That isn't right...
Ughhhh! Something is wrong than,
One of the techs may come in and request some specific information about the computer/network/OS causing the issues, as well as the specific Avast product and version. If no one has checked the "use a password box," and Avast is prompting for a password after a clean install, that is not right.
Is this customer on a network? If she is, has she talked to her network administrator or head person of that particular department? If it is part of a business network, I wonder if their firewall, all computers on the network are being blocked from adding additional installations? At several colleges that I went to and had computer training, they would lock down student installs to prevent abuses of the system.
Let's see what other information that Avast support people may have to say that could help you in this matter.
Jack