Attention: this tip is only for devices with a Ralink RT3090 WiFi adapter. If you are unsure whether you have a Ralink card, you can check it via Lenovo’s Product Configuration. If it doesn’t show a ‘Cbt RT3090 MOW M PCIE NB HMC WLAN’ entry, then this tutorial is not for you. UPDATE: you can use this small piece of software (modified from Lenovo installer) instead
The obvious way of installing the WiFi driver would be getting it from the official Lenovo support, but since it isn’t available there (WTF Lenovo?), the only place you can download it from is the manufacturer’s support page. If the provided link wouldn’t work navigate to Ralinktech.com > Support > Windows and look for RT309x. The latest version is 220.127.116.11 (04/12/2012).
Make sure that you tick the ‘install driver only’ option when you run the setup file.
Go to Device Manager >Network adapters and double click Ralink RT3090 802.11n WiFi Adapter. Switch to the Advanced tab and select ‘Continuously Aware Mode (CAM)‘ as Power Save mode. Go to the Energy management tab and untick ‘Allow computer to turn off this device to save energy’.
Save the settings and restart your computer. These options will ensure the maximum performance and connectivity for your Ralink wireless card.