One way to interpret your question is that you are attempting to add local users and groups to your SharePoint 2010,2013 Farm's site. One may want to do this if they are creating an isolated sharepoint farm accessible by extranet users and do not want to use a.d., live or ADFS accounts.
I was able to get the local users and groups to add by executing the following steps in and admin prompt of SharePoint PowerShell. 1) You must password enable the people picker Stsadm.exe –o setapppassword –password 2) Setting a default group will tell SharePoint to tie the local groups and users into the SharePoint Farm - site -> site settings -> people and groups -> Select group to make default -> settings -> Make default group 3) attempt to add the group or user to a site using people picker - i.e. servername. - The group may not be found right away, but you have now told SharePoint to look locally
1) It may take anywhere from 2-4 hours depending upon application pools to recycle for the above changes to take effect. So be patient, grab lunch and upon return try adding the groups or users multiple times in people picker if they do not resolve.
2) Check the registry key permissions for full control regarding the local groups wss_admin_wpg and wss_wpg. HKLM > Software > Microsoft > Shared Tools > Web Server Extensions > 14.0 or your version number of the hive > Secure