Dns Clean up

Start > Run > CMD
Right click and run as administrator, Then type the following:
ipconfig /flushdns net stop dnscache net start dnscache
To Refresh Group Policy:
gpupdate
You may also use:
gpresult
Start > Run > CMD
Right click and run as administrator, Then type the following:
ipconfig /flushdns net stop dnscache net start dnscache
To Refresh Group Policy:
gpupdate
You may also use:
gpresult