Delegate is a great way to implement Callback operation. But, interface is good for the implementation of Callback in different scenario which I have mentioned above. Please read carefully and understand the code snippets. I have also attached code files. Writing code is good but code with proper design approach increases the quality of code.
Windows Vista and Windows 7 make use of a c:\windows\winsxs folder to store backups of various install files and/or files replaced by updates. I'm not completely certain on everything Windows stores there.This seems to be completely separate from System Restore.he WinSxS\Backup folder: In previous versions of Windows, such as XP there was a component called 'Windows File Protection' which was used to make sure that all of the many system files were protected and backed up. These files were backed up in the %systemroot%\System32\dllcache folder.
Shadow Copy. Shadow Copy (also known as Volume Snapshot Service, Volume Shadow Copy Service or VSS) is a technology included in Microsoft Windows that allows taking manual or automatic backup copies or snapshots of computer files or volumes, even when they are in use. It is implemented as a Windows service called the Volume Shadow Copy service. A software VSS provider service is also included as part of Windows to be used by Windows applications. Shadow Copy technology requires the file system to be NTFS in order to create and store shadow copies.