I recently bought a mac mini with 2 hard drives in it; a solid state one & the other drive is a 500 gb mechanical drive. the mini is running OS Lion 10.7.3 when I tried to install something, I was prompted for a password, the prompt box had mac mini, & a blank box for the password. I could not install the software because I did not know the password. I then went into system preferences & created another administrator account with my name & password so I could install stuff. I then went to software update to update the mac. After the download was finished, I was told another administrator was using safari & I needed to close it. So I went to the mac mini administrator to get out of safari, only to be prompted for the password I did not know.