Question about a wired network

Okay after being tired about the unreliability of wireless i decided to run an ethernet cable from my router to my computer, my wireless connection was really messed up up and it usually crawls at terrible speed and disconnects a lot.

Im running Vista but my laptop keeps connecting automatically to various wireless networks, the only way I can get a connection through my cable is by disconnecting from a network and then plugging the cable in. Is there a way I can make sure my computer is connecting through my ethernet connection every time instead of wireless?, and also how to properly configure everything for ethernet?.
I was thinking that I could turn off my wireless adapter through device manager however im unsure if this would mess anything else up - also im not sure which it is, under network adapters I have 'Atheros Wireless Network Adater' and 'SiS Ethernet controller'.

If anybody has any ideas how I can set everything up so my ethernet connection works properly it would be greatly appreciated, thanks!.

 

Just disable the wireless connection, either in Device Manager or in Network Connections, that won't upset anything else.

 

Most laptops have an on off switch readily visible for wireless access near the keyboard.

 

Or a function key sequence if they don't have the physical switch.