Hello, Yesterday afternoon, I was able to logon to my Domain, access my files and my mapped drives from 2 Windows 7 Pro and 1 Windows 7 Ultimate. Late last night only 1 Windows 7 Pro could access the Domain, mapped drives and files with no problem. When I logon to the Domain with the other 2 machines, they have red "X's" on the mapped drives. If I want to access one of the mapped drives, I have type in an User name and password to logon to DC (The system detected a possible attempt to compromise security. Please ensure that you can contact the server that authenticated you). My DC (Windows Server 2008 R2 Enterprise w/SP1) is my DNS server and DHCP server. All Windows 7 machines have SP1. I can ping the server by IP address or server name. I do not know what happened but I would like to fix the mapped drive, files and domain access issue on the Windows 7 Pro and Windows 7 Ultimate Thank you in advance Ruben Cisneros

Hi, According to your description, it sound like it is related security settings. Is there an error when accessing the share folder with UNC? I suggest you try to system restore to check this issue could be fixed. If not, please take a look at the following thread: User gets an error "the system detected a possible attempt to compromise..." on any workstation logged into. Hope it helps. Alex ZhaoPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.