My suspicion: There's a local group "QlikView Administrators" on the machine where QVS is installed. If you (as OS user of the local machine) are member of this group the whole thing should simply work.
Aren't you using a domain? I don't think that it will work without a domain. I was meaning "add the domain user with which you are locally logged on to the QVAdmin group". Don't know how familiar you are with this matter (I myself only know basics) but I try to explain:
Let's say the domain is "KRALLO" and your user name is "MINO", then you could add "KRALLO\MINO" to the Local QlikView Administrator Group of the server machine. If you are locally logged in as "KRALLO\MINO" you will also be known by the server machine and granted access.
WITHOUT domain your local user would be e. g. LOCAL\MINO; you could create a user MINO on the server, and that would be SERVER\MINO, and LOACL\MINO is not equal to and will not be recognized as SERVER\MINO and you will still be asked for your credentials (or rejected).
Hope that was correct enough, not too much of theory and understandable .... Perhaps there IS another possibility, but I haven't thought of it too much ... perhaps anyone else here has an idea.