Author: Lou Adler 

How to determine whether the computer supports hibernation, the sleep states

Answer:

Check if hibernation is allowed 

1   function HibernateAllowed: Boolean;
2   type
3     TIsPwrHibernateAllowed = function: Boolean;
4     stdcall;
5   var
6     hPowrprof: HMODULE;
7     IsPwrHibernateAllowed: TIsPwrHibernateAllowed;
8   begin
9     Result := False;
10    if IsNT4Or95 then
11      Exit;
12    hPowrprof := LoadLibrary('powrprof.dll');
13    if hPowrprof <> 0 then
14    begin
15      try
16        @IsPwrHibernateAllowed := GetProcAddress(hPowrprof, 'IsPwrHibernateAllowed');
17        if @IsPwrHibernateAllowed <> nil then
18        begin
19          Result := IsPwrHibernateAllowed;
20        end;
21      finally
22        FreeLibrary(hPowrprof);
23      end;
24    end;
25  end;
26  
27  //Check if suspend is allowed 
28  
29  function SuspendAllowed: Boolean;
30  type
31    TIsPwrSuspendAllowed = function: Boolean;
32    stdcall;
33  var
34    hPowrprof: HMODULE;
35    IsPwrSuspendAllowed: TIsPwrSuspendAllowed;
36  begin
37    Result := False;
38    hPowrprof := LoadLibrary('powrprof.dll');
39    if hPowrprof <> 0 then
40    begin
41      try
42        @IsPwrSuspendAllowed := GetProcAddress(hPowrprof, 'IsPwrSuspendAllowed');
43        if @IsPwrSuspendAllowed <> nil then
44        begin
45          Result := IsPwrSuspendAllowed;
46        end;
47      finally
48        FreeLibrary(hPowrprof);
49      end;
50    end;
51  end;