Autodesk has released Update 2 for AutoCAD 2011 and AutoCAD LT 2011. 32-bit and 64-bit versions of this update can be found at the following links:
AutoCAD 2011 Update 2
AutoCAD LT 2011 Update 2
This update is only for AutoCAD and AutoCAD LT and cannot be applied to vertical products that are based on AutoCAD 2011.
Important: Before installing Update 2, you must install Update 1.1 for for your respective product. Update 2 does not include the fixes from Update 1.1 so both updates must be installed separately. If you have already installed Update 1.1, you can proceed with installing Update 2. The previous updates can be found at the following links:
AutoCAD 2011 Update 1.1
AutoCAD LT 2011 Update 1.1
Before installing Update 2, I strongly recommend you review the associated readme file for installation instructions, deployment notes, and details about the primary issues that are resolved by Update 2.