My Mac wont let me install anything!

[ruby77]

I'm not sure when this started happening, but everytime i try to download or install something (such as updating my itunes), a message box comes up saying "Type an administrator's name and password to allow Software Update to make changes". I type in my name and password and another box comes up saying "You must type an administrator's name and password to make changes to Software Update".

i have the only account on the computer and i have tried everything, please help!

 

[BlueRevolution]

Hmm, strange. Try creating a new administrator account ( -> System Preferences -> Accounts) and see if it works there.