Force windows 7 to use Wired LAN connections over wifi connections

I noticed on my Windows 7 pc that the pc connects to WiFi even when connected by a wired LAN. This causes some inconveniences, so I had to find how to turn it of.
To make sure windows 7 prefers LAN, follow these steps :

• Open the control panel
• Click Network and Internet
• Network and Sharing Center
• (left) Change Adapter Settings
• Hold the Alt key to make the menus appear and click Advanced
• Click Advanced settings
• On the Adapters and Binding tabs :
• Select the Local Area Connection (names might differ)
• Push the up arrow next to the list until the Local Area Connection is first in the list

Now just click OK and close all opened screens. Reboot might be needed. 

Menu Selection Gets Stuck on Screen

At work,

when I chose an item in a right click menu it stuck on screen,
It dissappeared when I locked and then unlocked the pc,
but reappeared the next time I selected an item. This does not work in windows 7 (and maybe 8), the quick workaround there is Start > Run :

tskill dwm

Right clicking the desktop and closing the menu also helped, but this were only workarounds.

I finally solved it :
Go into Windows Performance Options and de-select the option for "Fade out menu items after clicking."

In Vista, you can find it by right clicking My Computer > Properties > Advanced system settings (link on the left) > Advanced (tab) > Performance settings (button) > Visual effects (tab).

To cure it one in windows 7 you can set the corresponding monitor from 32 bit to 16 bit and back again, to remove one item. If it keeps happening, use the above solution.