I need an fix for installshield

When i try to install drivers, games, or anything it probably gets to 3/4 of the way done, it says,

" installation support fie directory/isrt.dll could not be installed acess is denied."

I WENT TO THE DIRECTORY THE FILE IS THERE

PLZ HELP

Try creating a new Administrator account.

Go into the Control Panel>User Accounts>Create a new account.

Name it anything you care to, make sure you choose to create the account as an Administrator. Reboot, log into the new Administrator account and try to install whatever it is you want to install here.

Let us know if this works please :).