Reason

You have turned off User Account Control or you are logged in using the default administrator account.

Solution

Do one of the following solutions:

Solution 1: Enable User Account Control.

1. In Control Panels, choose User Accounts.
2. Click "Turn User Account Control on or off".
3. Check the box to "Use User Account Control (UAC) to help protect your computer" and then click OK.
4. Restart your computer.
5. Install Adobe Reader 8.
   
   Note: You can turn off User Account Control after you successfully install Adobe Reader.

Solution 2: Run the installer in XP Compatibility Mode.

1. Download the Adobe Reader installer from the Adobe website. When you are prompted to run or save the file, choose save. Save the file to your desktop.
2. On the Desktop, right-click the AdbeRdr80_en_US file and then choose Properties.
3. Click the Compatibility tab.
4. Under Compatibility Mode, check Run this program in compatibility mode for: and choose Windows XP (Service Pack 2) from the drop down list.
5. Click Apply, then click OK to close the Properties window
6. Double-click the AdbeRdr80_en_US file and continue with the installation.

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