How to Clean Junk Files and Optimize Your PC

•
Ankit Kumar
Windows 11OptimizationStorage

The Problem

Temp folders, browser caches, and old installer leftovers pile up over months. The PC still has free space on paper, but everything feels sluggish—updates queue forever and apps take longer to open. This guide is about clutter, not a drive that is already completely full.

Drive almost full? If File Explorer shows a red bar on C:, start with how to free up space when C: is full. Come back here for routine maintenance once you have breathing room.

An Honest Expectation

Deleting temp files rarely makes a modern PC faster on its own. What it does is reclaim space, stop updates failing, and remove the clutter that makes real problems harder to spot. The genuine speed wins come from startup programs and background apps—covered at the end of this guide.

The exception is a nearly full SSD. Flash drives slow down markedly above roughly 90% capacity because the controller has less room to work with, so freeing space there does produce a measurable improvement.

Step 1: Let Windows Do the Safe Part

Storage Sense and Disk Cleanup handle the categories that are genuinely safe to remove, and they know what is still in use.

  1. Settings → System → Storage → Cleanup recommendations.
  2. Work through Temporary files, Large or unused files, Files synced to the cloud, and Unused apps.
  3. Turn on Storage Sense and click into it: set it to run Every week, delete files in the Recycle Bin after 30 days, and clear the Downloads folder Never (that setting has caught out a lot of people).

For the deeper categories, run the classic tool as administrator:

  1. Press Win + R, type cleanmgr, press Enter → choose C:.
  2. Click Clean up system files.
  3. Tick Windows Update Cleanup—often 5–15 GB after a feature update.
  4. Previous Windows installation(s) frees a lot, but only tick it if you are certain you will not roll back the last feature update.
  5. Delivery Optimization Files is safe to clear.

Step 2: Clear Browser Caches

On a machine used daily this is frequently several gigabytes per browser profile.

  • Chrome / Edge: Ctrl + Shift + Delete → time range All time → tick Cached images and files only. Leave passwords and cookies unticked unless you intend to sign out of everything.
  • Firefox: Ctrl + Shift + Delete → Everything → tick Cache → Clear Now.

If your browser has grown enormous, check for a bloated profile too: clear your browser cache and cookies.

Step 3: Empty the Temp Folders by Hand

  1. Press Win + R, type %temp%, press Enter. Select all with Ctrl + A → Delete. Skip anything Windows reports as in use—that is normal and harmless.
  2. Repeat with temp (no percent signs) for the system temp folder.
  3. Empty the Recycle Bin.

Do not delete folders under C:\Windows, C:\ProgramData, or AppData because a forum post suggested it. That is how people break user profiles and lose saved sign-ins.

Step 4: Find Forgotten Large Files

  1. Open File Explorer → This PC → in the search box type size:>1GB and press Enter.
  2. Sort by Size.
  3. Look for downloaded ISOs, old game installers, video exports, and virtual machine disks. Move what you want to keep to another drive.

For a visual map of where space actually went, WinDirStat or TreeSize Free shows nested folders far better than Explorer does—game shader caches and old Windows.old folders stand out immediately.

Step 5: Clean Up What Applications Leave Behind

  • Steam: Steam → Settings → Downloads → Clear Download Cache. Also right-click individual games → Properties → Installed Files to spot ones you no longer play.
  • Adobe / video editors: each keeps a media cache running to many gigabytes; the setting is in the app's own preferences.
  • Windows.old: removed by Disk Cleanup's Previous Windows installation(s) option, or it self-deletes 10 days after an upgrade.
  • Old restore points: System Protection → Configure → reduce Max Usage to 5–10%, which trims the oldest automatically.

Step 6: Where the Actual Speed Comes From

If the goal is a faster PC rather than free space, these two do far more than any file deletion:

And the full walkthrough: speed up a slow Windows 11 PC.

What Not to Do

  • Don't use registry cleaners. There is no measurable performance benefit on a healthy Windows install, and a bad clean causes application failures that are hard to trace back.
  • Don't defragment an SSD. Windows already runs the correct TRIM operation on a schedule; manual defragmentation only adds write wear.
  • Don't install a "PC booster" that runs constantly. A background optimiser is itself a background process, which is the thing you were trying to reduce.
  • Don't delete hiberfil.sys manually. Turn hibernation off properly with powercfg /hibernate off if you never use it.

Prefer a one-click pass? Ultimate Windows Cleanup Tool sticks to safe categories—temp files, browser cache, and safe registry leftovers—without touching your documents.

How Often

Once a month is plenty for most home PCs. Machines that edit video, compile code, or install and remove games frequently benefit from a temp clear every couple of weeks. Set Storage Sense to weekly and most of this happens without you thinking about it.

Related guides