I had this D420 for over 2 years and I can safely say it is one laptop with enough horsepower for the average business professional. It came with windows xp preinstalled, and I recently upgraded it to win 7. The upgrade went surprisingly smooth, with all devices (lapyop contained) being identified. The laptop itself is very lightweight and can be carried in a very small laptop bag (which will not feel like your carrying a bowling bowl) It is powered by a centrino processor and it can handle max capacity of 2 GB ram. Since the laptop is light weight, they decided to make the cd/dvd drive external. It plugs into the usb plug located in the rear of the unit. It seems to be slow to spin up, and is a bit of a hassle (if you forget to take it with you) Battery life is very good. I still get close to 3 hours on a system I had for 2 years. The big down side is heat. After 45 minutes the bottom of the laptop can get very hot! I suggest you leave some room to cool or get a laptop platform with cooling fans. Other than that a nice laptop for professional use.