What the cache is and why it slows your PC down
A cache is data Windows and your programs keep close at hand to answer repeated requests faster: browser pages, update packages, font previews, installer leftovers. That is useful while the cache is small and fresh. The problem starts when it grows unchecked: an overflowing browser cache makes antivirus scans longer, a bloated thumbnail cache delays folder opening, and leftover update files quietly eat gigabytes on your system drive.
On a typical two-year-old PC that was never cleaned, we measure 8–40 GB of pure cache and temporary junk. Nothing on that list is a user file — documents, photos and projects are never part of it. Clearing it is safe when you clear the right folders, and that distinction is exactly what this guide is about.
Windows system cache: what to clear
The safe targets are well defined. Each of them Windows rebuilds automatically the next time it needs the data, which is why removing them cannot break anything — it only costs a one-time rebuild.
- Temp folders (%TEMP%, C:\Windows\Temp) — installer leftovers and crash dumps
- Delivery Optimization cache — old Windows update pieces, often 5–15 GB
- Thumbnail cache (thumbcache) — rebuilt the first time you open a folder
- Prefetch and Superfetch data — Windows relearns your app usage in a day
- DirectX and GPU shader caches — rebuilt by games automatically
- Old Windows.old folder after a big feature update (10–30 GB)
The built-in way: Storage settings and Disk Cleanup
Windows 10 and 11 already ship a working tool: Settings → System → Storage → Temporary files. It shows a categorized list with checkboxes and sizes, then deletes what you selected. For a deeper pass, run the classic Disk Cleanup (cleanmgr) and click “Clean up system files” — that unlocks the Delivery Optimization cache and Windows Update leftovers that the Settings page keeps hidden.
The limits of the built-in path are worth knowing. It does not touch browser caches at all, it has no idea about caches of apps like Steam, Telegram or Adobe, and it gives you no preview of individual files — you are trusting the checkbox. That is fine for a monthly quick pass, and it is exactly where a dedicated cleaner earns its keep.
Browser cache: Chrome, Edge, Firefox, Opera
Every Chromium browser (Chrome, Edge, Brave, Opera, Yandex) clears its cache the same way: Ctrl+Shift+Del, choose “Cached images and files”, keep “Cookies” unchecked if you want to stay logged in, and pick “All time” as the range. In Firefox the shortcut is the same; the entry is called “Cached Web Content”. Clearing the cache logs nobody out — that is cookies, a different switch.
The catch is doing this across four browsers and several Windows user profiles by hand — and it returns in weeks. A cleaner with a dedicated browser module closes every installed browser's cache in one pass, including profiles of other Windows accounts, which the manual route rarely reaches.
DNS cache: the five-second fix for “site not found”
One more cache is invisible but causes real mysteries: the DNS resolver cache. When a site moves servers and your PC remembers the old address, pages randomly fail while other devices on the same network open them fine. Open a command prompt and run ipconfig /flushdns — that is the whole fix, instant and harmless.
The same category includes the Winsock catalog, which breaks after VPN or antivirus leftovers. Kleaner PRO puts flush DNS, reset Winsock and reset TCP/IP into one Network toolkit so you do not have to memorize the commands.
How to clear everything in one pass
The practical routine is to scan selected cleanup targets, review the detected paths and sizes, and remove only what you intend to delete. Kleaner PRO covers Windows temporary files, browser caches, logs, update-related caches, thumbnails and other defined targets. Scan time and reclaimable space vary by device; cleaning frees storage but does not guarantee a general performance increase.
If you enable scheduled cleaning, review the selected categories and age limits first. The scheduler can repeat configured cleanup tasks, but it cannot prevent all storage growth or guarantee a performance improvement; keep personal files and recovery data out of automatic cleanup.
Questions and Answers
Will clearing the cache delete my passwords or logins?
No. Passwords and sessions live in cookies and password stores, not the cache. Clear only “Cached images and files” and every site keeps you logged in.
How often should I clear the Windows cache?
A deep clean two to four times a year is enough for most people; a monthly quick pass if the SSD is small (under 256 GB). Automated weekly cleaning removes the question entirely.
Why does the cache grow back so fast?
Because it is supposed to. Browsers and Windows rebuild it constantly — the point is keeping it bounded, not empty. That is why scheduled cleaning beats one-off purges.
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