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.
Notes about the XLSX file extension: Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues. The XLSX file type is primarily associated with 'Excel' by Microsoft Corporation. This is the new format for Microsoft Office documents. It is a combination of XML architecture and ZIP compression for size reduction.