Thats the funniest problem
I have to give admin access to other user too. But when he logged in i logged off automatically so
after some finding i m able to alow multiple session per user by changing "Restrict Each User To a Single Session " to No
But it create problem he is doing java testing & multiple session is not supported by the application he is using & give unexpected errors .
after some research we finally understand this problem now I forgot that from where i allowed multiple connection . and after checking all GPO [U can also change setting from SPO but it wont work , I dont know why MS put that property which dont work] & local security etc for 5 days.
I googled but again no solution :(
FYI : I googled means I searched google , yahoo & msn .
However Finally I Hit again to administrative tool & changed the setting.
Start => administrative tool-> Terminal Services -> Terminal Services Configuration -> Edit Setting -> Restrict Each User To a Single Session