It wont let me install the printer?

I am trying to install a HP all-in-one series printer but it just pops up
telling me that I dont have administrator privilages. I am the only one who
uses this computer, as it is mine. How do I fix this problem? I need to print
today.

Which version of VISTA

Which model of HP AIO?

Have you downloaded HP VISTA software for the printer or used an
existing CD? If the latter is it for VISTA or XP?

Give us the answers and I'm sure help will be forthcoming.