So you are running Windows and it do install but at a later visit it still doesn't work?
If it do install I assume that answer the question. Why it doesn't work I have no idea. Tried typing about
lugins (in your browser url field) and see whatever it's loaded? Tried different browsers? What OS are you running?
If it would had been a game I could had guessed that maybe it required some hardware feature (graphics related) not available but I guess that's not the case.
On Linux you'd have to install Moonlight instead and I assume that may not have all the features of Silverlight, but I doubt your (x86?) NetBook are running Linux? (Possibly ChromeOS?) If such installing Windows would be an option.
If it's an ARM-based laptop and run Android you might be out of luck.