Your network might be fine, just not properly tuned.

Windows utility maker Stardock today announced a new app, Connection Manager, that visualizes network activity.

Windows only: Avanquest Connection Manager, previously a $30 app, is now a free utility that could be seriously convenient for laptop users. The app lets you create profiles for your different wi-fi ...

There are many reasons for this problem; one of the reasons is that Windows Update failed to install or update the Network drivers, in that case, you have to update the required driver manually.