Download and Install AIT 2010 SP1 because it is a prerequisite for Windows 7 support.
Try to reregister Mold design addin.
1. Select Command Prompt and RMB menu then click Run as administrator.
2. Input command regsvr32 and drag molddesign.dll in bin folder of Inventor 2010 installation into administrator command prompt dialog.
3. Once you have registered successfully, Launch Inventor to check for Mold Design in Addin Manager.