Should your adapter not be running automatically upon startup, you may want to begin by checking to see if a particular software is causing conflicts. There is one known as Bonjour, which is commonly included with applications such as Apple iTunes and Adobe Suite, among others. This is often known to cause such issues. Bonjour locates devices such as printers and other computers, identifying the services that these devices offer on a local network using multicast Domain Name System (mDNS) service records. However, this feature is not essential for all users.
Method 1: Removing the software through run box
Update 2013/12/31: Newer versions of Bonjour can just be uninstalled from “Programs and Features” (Add/remove programs). However, each time you update iTunes you have to remove it again. “%PROGRAMFILES%\Bonjour\mDNSResponder.exe” -remove regsvr32 /u “%PROGRAMFILES%\Bonjour\mdnsNSP.dll” After you restart, you can safely delete the Bonjour folder without errors.
Method 2: Disable Bonjour Service
Method 3: Uninstall from Control Panel
If removing Bonjour did not resolve the issue, then reinstalling the drivers for the Ethernet adapter could remove any type of conflict with software and resolve the issue.
Method 4: Reinstalling driver for the Network Adapter
Last but not least, if the issue presented is not related to a software or driver conflict, then it is very possible that it is hardware related.