Here’s a clean, safe, and repeatable way to reclaim disk space on Windows—starting with the built-in tools, then moving to manual cleanups and power-user options. I’ll also note third-party “space visualizers” like WizTree (“tree wiz”) and TreeSize.

1) Start with Microsoft’s built-in cleanup #

A. Disk Cleanup (Cleanmgr) #

1. Press Win + S, type Disk Cleanup, open it.
2. Select the drive (usually C:).
3. Click Clean up system files (rerun, pick C: again).
4. Check common safe items:
   • Windows Update Cleanup (can be several GB)
   • Delivery Optimization Files
   • Temporary files, Thumbnails, Recycle Bin, Temporary Internet Files
   • Previous Windows installations (only if you’re sure you won’t roll back)
5. Click OK → Delete Files.

Disk Cleanup removes temporary and update leftovers; using Clean up system files exposes deeper system items (like Windows Update cleanup) that reclaim the most space. (Microsoft Support, Microsoft Learn)

B. Storage (Windows 10/11) + Storage Sense (optional automation) #

• Go to Settings → System → Storage to see what’s taking space and delete Temporary files directly, or enable Storage Sense to auto-clear temp files, Recycle Bin, and cloud-synced local copies on a schedule. (Microsoft Support)

2) Manual cleanups that are safe #

Tip: Close apps and browsers first; some files won’t delete while in use.

A. Empty the big obvious places #

• Recycle Bin (right-click Bin → Empty).
• Downloads: Move large installers/videos you no longer need or archive them to another drive.
• Videos/Pictures/Documents/Desktop: Sort by Size and archive what you can.

B. Clear user + system temp folders #

• Press Win + R, type %TEMP%, Enter, select all, Delete (skip files in use).
• Go to C:\Users<your-name>\AppData\Local\Temp and delete contents.
• (Admin) C:\Windows\Temp — delete what you can; skip files in use.

C. Per-app caches (optional) #

• Browsers (Edge/Chrome/Firefox): clear cache/history via their settings if needed (this may sign you out or clear offline content).
• Game launchers (Steam/Epic) and design tools (Adobe) can accumulate caches—use their built-in “clear cache” options.

D. OneDrive / cloud sync #

• If you use OneDrive, right-click large folders → Free up space to keep them online-only while removing local copies. You can also let Storage Sense do this automatically. (Microsoft Support)

3) Go deeper (power-user but safe) #

A. Windows component store cleanup (WinSxS) #

Run Command Prompt (Admin) and execute:

DISM.exe /Online /Cleanup-Image /StartComponentCleanup

This trims superseded Windows component versions and can free several GB—safer than manually touching system folders. (Microsoft Learn)

B. Uninstall large/unused apps #

• Settings → Apps → Installed apps (or Apps & features). Sort by Size, uninstall what you don’t need (especially old games, trial suites, duplicate editors).

C. Optional: Disable Hibernation (if you never use it) #

• Command Prompt (Admin):

powercfg -h off

This deletes hiberfil.sys (often several GB) but disables Hibernate and Fast Startup. Only do this if you’re sure you don’t need those features.

4) Safely exploring AppData and other locations #

These locations often hold large temporary or cache files. Stick to the Temp and obvious cache folders; avoid deleting anything you don’t recognize.

• C:\Users<your-name>\AppData\Local\Temp — safe to empty.
• C:\Users<your-name>\AppData\Local\Packages — UWP app caches; you can sort by size and clear obvious Temp/Cache subfolders for apps you know.
• C:\Users<your-name>\AppData\Local\Microsoft\Windows\INetCache — browser/legacy web cache; safe to clear with browsers closed.
• C:\Windows\SoftwareDistribution\Download — prefer using Disk Cleanup’s Windows Update Cleanup instead of deleting here manually. (Microsoft Support)

5) Visualize what’s actually huge (“tree wiz” & friends) #

When you’re not sure what is eating space, use a visual analyzer to find the biggest folders/files quickly.

• WizTree (often referred to as “Tree Wiz”): extremely fast; reads the NTFS Master File Table directly for near-instant scans. Great for spotting giant folders and duplicates. (Free for personal use; supports network/non-NTFS too.) (diskanalyzer.com)
• TreeSize (Free/Personal/Professional): classic tree and treemap visualizations; excellent reporting and duplicate search in paid versions; a solid, enterprise-friendly option. (jam-software.com)
• WinDirStat: popular open-source treemap with a simple “what’s big?” view. Also available via winget. (windirstat.net)

How to use them effectively

1. Scan C: (and any data drives).
2. Sort by size to find top space hogs (VMs, ISOs, old downloads, video projects).
3. Right-click to open in Explorer and delete or move what you recognize.
4. Be cautious in Windows and Program Files—prefer the built-in tools for system files.

Quick checklist (repeat monthly or quarterly) #

• ☐ Run Disk Cleanup → Clean up system files. (Microsoft Support)
• ☐ Clear %TEMP% and C:\Windows\Temp.
• ☐ Review Downloads, Videos, Desktop for large items.
• ☐ Uninstall unused apps/games.
• ☐ Run DISM /StartComponentCleanup (optional). (Microsoft Learn)
• ☐ Use WizTree/TreeSize/WinDirStat to catch any stragglers. (diskanalyzer.com, jam-software.com, windirstat.net)

If you want, tell me your Windows version and how much space you need to free—I can tailor the exact boxes to tick in Disk Cleanup and which folders to target first.