title: How to change time zone settings using windows api
body: <p>I need to change DST and time zone via API in my application. 
  I modified &amp; copied example of "SetTimeZoneInformation" usage by the end of the following link and have run it:
  <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/ms724944(v=vs.85).aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/windows/desktop/ms724944(v=vs.85).aspx</a></p>
  
  <p>I am assuming that my time settings should reflect on my time settings in tray or control panel. But nothing happens.</p>
  
  <p>Following thing also should be noticed.</p>
  
  <p>This code modifies "HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation" key content.
  And there are no changes in "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\my time zone" thread. But this is what I am looking for!</p>
  
  <p>Is there any way to modify "my time zone" using API in C++?</p>
  
  <p>Added (from the answer that should have been edited in here):</p>
  
  <p>So, actually, my goal is to make my application to work under Win7. Existing functionality uses MANUAL DST support. Thus, I need somehow synchronize this manual DST and GMT offset settings with Win7 ones. As I understood, SetTimeZoneInformation function just tries something like to find time zone from the existing set of time zones according to my input. If there is no time zone equal my input, Win7 uses default one, UTC-12 for instance, and notifies user that "current time zone is not recognized".</p>
  
  <p>So, what approach should I use to realize that?</p>