OP, please make sure you have installed DirectX 9 latest runtime (June, 2010) version and all the Visual C++ versions (both x86 and x64 versions). And regarding switchable Graphics, it should automatically activate the dedicated GPU once any graphics intensive task is fired. However, in the AMD control panel, under the Configure Switchable Graphics option, you can manually add the executables and assign any of the the available GPUs (either HD 3000 or HD 8750M) to it to make it an obvious thing. For any games, it should be the dedicated GPU, to be selected under that configuration to make sure it will always run on AMD GPU.
However, these mobility versions of the Drivers actually disable a lot of features available in their desktop version for compatibility and stability issues as different vendors use different settings for same mobility GPU. For Intel CPU + AMD GPU based Laptops, there are plenty of Modded drivers available which can unlock all those features and provide better performance.
Leshcat’s Catalyst UnifL Catalyst drivers are currently the best for Intel + AMD GPU combination. Download the latest 13.6 Beta 2 Modded driver form here: *leshcatlabs.net/