An issue was reported to me where some users were trying to use explorer view to copy some files in sharepoint libraries in windows server 2012 and were getting an error "This site is not present in trusted site list". I checked and found that the site was present in the trusted site list in browser. The next thing I moved was to verify the webclient service. When I opened services.msc I found no service named as webclient. Hence the first action was get the webclient services installed in the server, to do this I followed the following steps:

1. Open the server manager.
2. Go to add features and select Desktop experience as shown in the screenshot:

3. Restart the server and allow the server to configure itself.
4. Once restarted go to Services.msc and start webclient services.