windows server 2008- server 2008r2 - windows 7 and windows 8- cuncurrent remote desktop,

   1. Start - run - regedit
   2. Check out the follwoing registry key
      HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TerminalServer
   3. If the fSingleSessionPerUser value doesn’t exist, create a new DWORD value named fSingleSessionPerUser
   4. Open the fSingleSessionPerUser value. The possible values for this setting are as follows:
      0×0 Allow multiple sessions per user
      0×1 Force each user to a single session
   5. save this


after you will login remotely multi user