Hi Charan, Linkey adware creates two entries in Control Panel - "Linkey" and "Settings Manager". Be sure to uninstall them both. In a case when uninstaller doesn't function you can use third party tools:

CCleaner
Download, install and run CCleaner. After launching the program select "Tools". In the uninstall programs list select the program you want to uninstall and click the "Run Uninstaller" button.

Revo Uninstaller
Download, install and run Revo Uninstaller. After launching the program select the program you want to uninstall from the list and click on the "uninstall" button.

IObit uninstaller
Download, install and run IObit Uninstaller. After launching the program select the program you want to uninstall from the list and click on the "uninstall" button.

After successfully uninstalling Linkey and Settings Manager applications be sure to reset your Internet browser settings following this removal guide https://www.pcrisk.com/removal-guides/7805-default-search-net-virus