The reason for that is the third part of why the component store gets so large.Ĭomplaining about the size of the /winsxs folder, tooĪ coworker recently received his every two year work laptop refresh and was in the middle of loading his new laptop with Vista.

The higher version of the component is projected onto the system, but the older version in the store isn’t touched. When we update a particular binary we release a new version of the whole component, and that new version is stored alongside the original one in the component store. In previous versions of Windows the atomic unit of servicing was the file, in Windows Vista it’s the component. That explains why the folder starts off big, but not why it gets larger over time – the answer to that question is servicing. This also accounts for why you will no longer be prompted for media when running operations such as System File Checker (SFC), or when installing additional features and roles. So looked at from that perspective, the WinSxS folder is really the entirety of the whole OS, referred to as a 'flat' in down-level operating systems. Let me repeat that last point – there is only one instance (or full data copy) of each version of each file in the OS, and that instance is located in the WinSxS folder. The WinSxS folder is the only location that the component is found on the system, all other instances of the files that you see on the system are “projected” by hard linking from the component store.

Each component has a unique name that includes the version, language, and processor architecture that it was built for. What is the Windows Side By Side folder? Well, that'sĪll of the components in the operating system are found in the WinSxS folder – in fact we call this location the component store. A Vista virtual machine I use only has a 10 GB virtual hard disk - and I'm worried about it running out of space over time.Īnd the primary culprit is that /winsxs or 'Windows Side-By-Side' folder.

Service pack backup files