Unable to elevate to administrative rights, error 6 (Adobe Digital Editions 4 Installation Problem)

I have a Windows 7 computer and I am having some issues installing Adobe Digital Editions 4. Every time I try to install the software, a box pops up that says "Run as - You may not have the necessary permissions to use all of the features of the program you are about to run. Run this program as a different user or continue to run the program as a different user." It will not accept my username and password to login as an administrator and it gives me another message saying "Unable to elevate to administrative rights, error6."

Can anyone explain what I should do to install the program?