Administrator rights

Recently I have been getting a weird instances when trying to install software. I'm being met with: "you do not have the rights..."

I am currently logged in as administrator.
When I try to "run as administrator" I get the same message.

This came up in a recent attempt to install Adobe Reader:

"IMAIL cannot be opened. An error is preventing this key from being opened. Details: Access is denied."
IMAIL is sitting here:
local machine\software\microsoft\windows\current version\run\optional components\IMAIL

So I thought maybe it was the account I have. I created a new Administrator account. Logged out of old account. Logged in to new account, went through same installation process of Adobe Reader and got the same error.

Running Vista SP2
32 Bit

HELP!
THANKS
GVG