Alienware released the M17x series of laptops on June 2nd, 2009 as the first Alienware/Dell branded system. The M17x 788F is a first generation Alienware/Dell build and comes with an Intel Core 2 quad-core processor and integrated Nvidia GeForce 9400M 256MB graphics processor.
Your computer may be running slow because you have too many programs running in the background. There is information on the troubleshooting page on disabling startup programs.