SolidWorks 2010 SP1 and later is qualified on Windows 7 Professional, Ultimate and Enterprise. For more details, refer to http://www.solidworks.com/sw/support/SystemRequirements.html .
You can also verify your graphics card and driver using http://www.solidworks.com/sw/support/videocardtesting.html.
For laptop configurations, we rely on the vendor to give us graphics card drivers for the supported operating systems. The Dell M4300 and M65 do not officially have a graphics card driver for Windows 7, so we do not test Win7 for your specific configurations. Refer to http://support.dell.com/support/downloads/index.aspx?c=us&cs=28&l=en&s=dfb for the operating systems supported by Dell laptops.