High CPU Usage (w3wp.exe) SharePoint 2013 Sites

We have installed Visual Studio 2013 in SharePoint 2013 development Server and restarted the server. Now we experience slowness to load the SharePoint web site.

1. Reset the IIS
2. Recycle the Application Pool

I tried to open some list URLS and returns the error "An unexpected error has occurred."

try open the site in SharePoint Designer 2013 and it's failed.

Any hope to resolve the issue.

Thanks