# What is safe to delete on Windows — and what is not | Rain Cleaner > A category-by-category answer: temporary files, Windows Update leftovers, the WinSxS folder, restore points, hibernation file and the recycle bin. What you get back, and what you give up. - Product: Rain Cleaner 2.7.1 — Cleans, explains, hides nothing. - Publisher: T. Vasilev - Platform: Windows 10, Windows 11, Windows Server - Price: 0 EUR (Pro not on sale yet) - Download: https://raincleaner.eu/download · Portable: https://raincleaner.eu/download/portable - Canonical: https://raincleaner.eu/guides/what-is-safe-to-delete-windows ## What is safe to delete on Windows and what is not Disk cleanup tools show you a number and a button. The number is the easy part. Here is what is behind each category, and the ones where the right answer is to leave them alone. ### Safe, and you lose nothing These are files Windows and your programs would recreate anyway. Deleting them costs you nothing but the seconds it takes to rebuild a cache. This is where most of the space usually is, and it is also where most cleaners stop explaining. - Temporary files in your user profile and in the Windows temp folder. - Browser cache — pages load once more from the network, then it is back. - Thumbnail and icon caches, rebuilt the next time you open a folder. - Crash dumps and error reports, once you are past the crash. - Delivery Optimization files — pieces of updates kept to share with other PCs on your network. ### Windows Update leftovers: safe, with one condition After an update installs, Windows keeps the old files so you can uninstall that update. Once you are sure the machine is fine — a few days of normal use — these are dead weight, and on a machine that has had a feature update they can be many gigabytes. The condition is exactly that: if you delete them, you can no longer uninstall those updates. If a monitor has been flickering since Tuesday, deal with that first. ### WinSxS: do not delete it, and do not trust anyone who says you can The WinSxS folder looks enormous in Explorer and it is one of the most common pieces of bad advice on the internet. Most of what you see there is not really there — Windows uses hard links, so the same file is counted many times over. Deleting from that folder by hand breaks Windows in ways that are hard to repair. There is a supported way to shrink it, and only one: the component cleanup that Windows itself performs, which removes superseded component versions and nothing else. - Supported: Dism /Online /Cleanup-Image /StartComponentCleanup. - Never: deleting anything inside C:\Windows\WinSxS by hand. ### Where the honest answer is: keep them System restore points are the most valuable thing on a Windows disk that is not your own files. They are the difference between a bad driver being a twenty-minute annoyance and a lost evening. A cleaner that offers to delete them to show you a bigger number is optimising for the number, not for you. The hibernation file is the other one people get wrong. Yes, deleting it frees several gigabytes. It also turns off hibernation and, on most laptops, fast startup with it. If you use either, that is a bad trade for disk space you were not short of. - Restore points — keep at least the most recent one, always. - Hibernation file — only delete it if you never hibernate and never use fast startup. - The Downloads folder — no cleaner should touch it, and Rain Cleaner does not. ### What Rain Cleaner does with all this Every category it finds comes with the explanation attached — what the files are, what you get back, and what you lose. If a category has no explanation written for it, the scan fails rather than showing you an empty box with a checkbox next to it. Categories with a cost are not pre-ticked. Restore points appear in the list with a “better left alone” note rather than a checkmark. And deletion happens only inside an explicit list of folders: the root of a drive, junctions, symlinks and protected user folders are refused outright. ### Quick questions **How much space will I actually get back?** On a machine that has never been cleaned, typically a few hundred megabytes to a few gigabytes, most of it browser cache and update leftovers. Anyone promising tens of gigabytes is counting things you should keep. **Does cleaning make my PC faster?** Almost never, and it is worth being blunt about it. Free disk space helps when the drive is nearly full. Otherwise you are reclaiming space, not speed. **Is the registry worth cleaning?** No. Registry cleaners have been solving a problem that stopped mattering fifteen years ago, and a wrong deletion there is a real risk. Rain Cleaner does not touch the registry for cleaning. --- Other languages: [English](https://raincleaner.eu/guides/what-is-safe-to-delete-windows) · [Български](https://raincleaner.eu/bg/guides/what-is-safe-to-delete-windows) · [Deutsch](https://raincleaner.eu/de/guides/what-is-safe-to-delete-windows) · [Español](https://raincleaner.eu/es/guides/what-is-safe-to-delete-windows) · [Русский](https://raincleaner.eu/ru/guides/what-is-safe-to-delete-windows) · [Türkçe](https://raincleaner.eu/tr/guides/what-is-safe-to-delete-windows)