Can not scan Nvidia Display card

My laptop is Inspiron 17R SE 7720 with Nvidia 550M card and intel HD 3000, weeks ago i found games run not so smoothly so I checked Device Manager and found Nv card did not work properly. I re-installed drive and everything worked fine. Now my laptop sucks in game again and I can not find NV card in Device Manager, and  Nvidia setting panel says "an NVIDIA graphics card was not detected in your system. I will try do mother board drive and as well as wait for any other solutions.