Hello, KB981793 windows update in XP causes my application to crash, but works fine with Win7/Vista environment. I understand from microsoft site that this is a cumulative time zone update. Is there any difference in the mechnism in which time zones are handled in WinXP and Vista/Win7? If the update is going to be on the windows registry, then why there are different updates for different operating system? Thanks in advance. Thanks, Vignesh