No internet even though connected to Wifi network

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http://askubuntu.com – I am very new to Ubuntu (like yesterday!) and decided to run a dual boot of Ubuntu using the Windows installer. After some initial problems, it was installed successfully. However, I am only connected to the internet for about two minutes time consecutively, as the WiFi connection seems to become dead then. Other devices on the same WiFi network can access the internet just fine at that time. When I'm using Windows 8 on the exact same machine, I'm also not experiencing this issue. The internet connection on Ubuntu works for just a few minutes allowing me to open one or two web pages or to fi (HowTos)