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Find What Is Filling Your SSD With WizTree

A 2 TB drive with 40 GB free and no obvious culprit. WizTree reads the file table directly, so the whole disk is mapped in seconds - then you delete with intent.

by@guidox updated:10/30/26 time:15 min level:Beginner tested on:Windows 11 24H2, 2 TB NVMe works on:Windows 10, Windows 11 tools:WizTree
TL;DR

Scan the drive with **WizTree**, sort by **size**, and look at the top of the tree before deleting anything. The biggest wins are usually **WinSxS** backups, hibernation files, game shaders and an old Windows.old folder.

Before you start

Requirements

  • WizTree from the official site (free for personal use)
  • Admin rights - without them the scan is slow and limited
  • Ten minutes before you delete anything
Step by step

Instructions

01

Scan the right volume

Start WizTree, pick the full drive - not a folder - and press **Scan**. It reads the NTFS master file table directly, so a 2 TB drive is done in seconds instead of an hour.

tipRun it as administrator. Without that WizTree falls back to walking directories and takes as long as every other tool.
02

Read the treemap, not the list

The treemap on the right shows the drive as rectangles scaled by size. Hover the big blocks first - one folder is usually responsible for a third of the drive.

03

Know the usual suspects

The biggest files on a normal Windows machine are the page file, hiberfil.sys, one or two game folders and the shader caches. None of them is a surprise, and each has an honest way to shrink it.

%SystemDrive%\iberfil.sys
%SystemDrive%\agefile.sys
%LOCALAPPDATA%\3DSCache
%LOCALAPPDATA%\VIDIA\XCache
⚠ warningDo not delete hiberfil.sys or pagefile.sys by hand - Windows owns them and will recreate or break.
04

Shrink the caches properly

Clear the GPU shader caches in **Disk Cleanup** and in the NVIDIA or AMD control panel instead of deleting the folders. They rebuild on demand, which costs a little stutter once.

cleanmgr > DirectX shader cache
05

Turn off hibernation if you never use it

Sleep and hibernate are not the same mode. If you only ever sleep, disabling hibernation removes a file the size of your RAM.

powercfg /hibernate off
⚠ warningFast Startup depends on hibernation. Turn it off as well, or the boot gets slower than before.
06

Clean the leftovers

Windows.old, old update payloads and the delivery optimisation cache together are often 30 GB. Use **Storage Sense** and **Disk Cleanup > Clean up system files**, and let Windows decide what is safe.

Settings > System > Storage > Temporary files
tipDelete Windows.old only after a week of stable running - it is your rollback path.
Troubleshooting

Common issues

The scan is slow

WizTree is not running as administrator. Close it, right-click and choose Run as administrator.

A folder shows a huge size but is empty

Hard links and junctions. WizTree counts them where they really live; the size is not duplicated space.

Space disappears again within days

Something writes constantly - check the Windows event log size, shadow copies with vssadmin list shadowstorage, or a sync client.

Deleting a game folder did not free the space

A launcher still holds the files open, or the game lives on another library path. Uninstall through the launcher instead.

FAQ

Frequently asked

WizTree or WinDirStat?

WizTree because it reads the file table directly and is seconds instead of minutes on a full drive. WinDirStat is portable and open source.

Is the free version enough?

Yes, for personal use. The paid licence adds commercial use and scheduled scans.

How to undo this

Nothing to undo - the tool only reads. Any file you deleted is gone; restore it from the recycle bin or from your backup.

Changelog · 1 entry
  1. 2026-10-30
    First version
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