I have installed fresh Ubuntu 16.04 x64 in Dell optiplex 360
Configuration : Intel(R) Core(TM)2 Duo CPU E7400@2.80Ghz RAM :3GB RAM HDD:80HDD Display : 82G33/G31 Express Integrated Graphics Controller
When i start the pc it works completely fine after an hour it slows down and freezes sometimes then the screen goes black and again resume automatically for which i have to wait.Opening new tab or clicking on new tab in Google chrome or Firefox freezes the mouse pointer and goes black and resumes after sometime.Mouse pointer lags while moving and switching to different window hangs after clicking.
I use netbeans,filezilla,Google Chrome,Firefox etc and the
swap memory is 2GB.
Please help me in finding solutions