The is not available as a single "all-in-one" official full installer from Adobe. Instead, you must first install the base version (11.0.0) and then apply the 11.0.23 update patch. Recommended Installation Steps
First, install the base Adobe Reader XI (11.0.0). download adobe reader xi 11.0.23 offline installer
You can obtain the base standalone installer (v11.0) from the Adobe FTP Archive or authorized distribution sites like ProDesignTools Step 2: Download the 11.0.23 Update Patch The is not available as a single "all-in-one"