thanks for your valuable suggestions.
let me tell you actual problem.
i just received new laptop from my office that is IBM Thinkpad E450 windows 8.1 core i3, 4gb ram. builtin graphics.
before I was using desktop pc dell optiplex 3020 with core i3 win 8.1
comparing these 2, laptop is two slow, in booting, processing.
i am user of CAD, Office, MS Project, other related apps.
so I planned to upgrade ram.