Guides for Windows Disk Cleanup

The list below is grouped by the moment you're in: getting your bearings, dealing with an external or networked drive, and the point right before you delete anything. If you're new to this altogether, the how to use TreeSize walkthrough is a better first stop than any single guide here.

• Scan an external drive — USB speed, file systems, and what backup drives usually hide.
• Scan a network drive or share — UNC paths, permissions, and why SMB scans crawl.
• Run TreeSize as administrator — why elevation changes what a scan can actually see.

Written and tested by jam-software.org Editorial Team, Windows Storage Editors. We reproduce the documented task on Windows, compare storage totals with Windows file properties, and verify product-specific statements against first-party documentation.

• JAM Software TreeSize product documentation
• TreeSize online manual
• Microsoft Windows support

Read the complete testing and corrections policy.

• Install TreeSize on Windows 11: Step-by-Step Guide — Learn how to install TreeSize on Windows 11, review setup choices, and complete the first disk scan safely.
• Install TreeSize on Windows 10 Safely — A focused walkthrough for installing TreeSize on Windows 10 and confirming that the first scan works correctly.
• Run Your First TreeSize Scan — Run a first TreeSize scan, choose the correct target, and interpret the initial folder-size results.
• TreeSize Interface Explained — Understand the folder tree, size columns, charts, filters, and navigation controls in the TreeSize interface.
• TreeSize Settings Guide for Windows — Configure practical TreeSize display, scan, unit, sorting, and confirmation settings without changing Windows files.
• Use TreeSize From the Windows Context Menu — Open a folder or drive in TreeSize from File Explorer and fix a missing context-menu entry.
• Run TreeSize From a USB Drive — Prepare and use a portable TreeSize copy from a USB drive while keeping settings and scan scope predictable.
• Uninstall TreeSize Cleanly on Windows — Remove TreeSize from Windows, check optional settings, and confirm that personal files remain untouched.

• Find the Largest Folders in Windows 11 — Identify the folders using the most space in Windows 11 and distinguish user data from protected system content.
• Find Large Video Files on Windows — Locate oversized MP4, MOV, MKV, and other video files by combining size sorting with file-type filters.
• Find Large ZIP and ISO Files — Find archived ZIP, 7Z, RAR, and ISO files that can quietly consume large amounts of storage.
• Find Old Large Files on Windows — Combine file age and size to find large, inactive files while avoiding unsafe deletion decisions.
• Analyze C Drive Space Usage — Scan the Windows C drive, identify the main space consumers, and decide which areas need closer review.
• Folder Size: Command Line vs TreeSize — Compare command-line folder-size checks with a visual TreeSize scan for repeatable Windows storage analysis.
• Allocated Space vs File Size Explained — Understand why Size and Allocated Space differ on NTFS drives and how that affects disk-usage decisions.
• Scan Hidden Files and Folders — See when hidden and protected files affect storage totals and why elevated access may be required.
• Sort Files and Folders by Size in TreeSize — Use size columns and descending sort order to move from a broad disk scan to the biggest actionable items.
• Filter Files by Extension in TreeSize — Narrow a disk scan to selected file extensions such as ISO, PST, VHDX, ZIP, or video formats.

• Free Up C Drive Space Safely — Use a measured scan-review-delete workflow to recover C drive space without targeting required Windows files.
• Clean the Downloads Folder Safely — Review installers, archives, documents, and duplicate downloads before reclaiming space from the Downloads folder.
• Analyze Large Windows User Profiles — Find which user profiles and profile subfolders consume storage on a shared Windows PC.
• Review Temporary Files Safely — Distinguish Windows temporary storage from application data and choose the safer cleanup tool for each category.
• Move Large Files to an External Drive — Plan, copy, verify, and only then remove large personal files from the original Windows drive.
• Understand OneDrive Files and Disk Space — Interpret OneDrive online-only, locally available, and always-kept files when analyzing Windows storage.
• Check the Windows.old Folder Size — Measure Windows.old, understand why it exists, and use supported Windows controls if it can be removed.
• Pagefile.sys and Hiberfil.sys Disk Usage — Understand why pagefile.sys and hiberfil.sys can be large and why they should not be deleted like ordinary files.
• NTFS Compression and Reported Disk Space — Understand how NTFS compression changes allocated space and when compression is unsuitable.
• Low SSD Space: What to Check First — Prioritize safe storage checks when a Windows SSD is nearly full and avoid random deletion.

• Scan NAS Storage From Windows — Connect to a NAS share, choose an appropriate scan scope, and interpret permissions and network limitations.
• Scan a Mapped Network Drive — Scan an existing mapped drive letter and troubleshoot missing folders or incomplete totals.
• Scan a UNC Network Path — Analyze a network share by UNC path without relying on a persistent mapped drive letter.
• Why a Network Drive Scan Is Slow — Separate network latency, server load, antivirus scanning, permissions, and file-count effects during remote scans.
• Scan Multiple Drives Efficiently — Plan separate scans across several Windows volumes without mixing unrelated storage decisions.
• Standard User vs Administrator Scans — Understand how access rights change scan completeness without granting unnecessary privileges.
• Analyze Shared Folder Disk Usage — Measure shared-folder usage while accounting for access restrictions, ownership, and active users.
• Use TreeSize for a Storage Audit — Create a repeatable inventory process for business storage reviews without treating scan output as an automatic deletion list.

• Export TreeSize Results to CSV — Export scan results to CSV and preserve the scan scope, units, and date needed to interpret the report later.
• Open TreeSize Export Data in Excel — Import TreeSize data into Excel without losing numeric size values or mixing folder and file records.
• Create a TreeSize PDF Report — Prepare a readable PDF snapshot of disk usage for sharing, review, or record keeping.
• Compare Disk Space Usage Over Time — Use consistent scan scope and saved reports to identify which folders are growing.
• Plan Scheduled Storage Scans — Design a recurring storage-check workflow and understand which TreeSize edition features may be required.
• Read TreeSize Charts Correctly — Use bar, percentage, and hierarchy views without confusing visual prominence with deletion safety.
• Document a Windows Disk Cleanup — Record the before-and-after evidence needed for a repeatable personal or business cleanup process.

• Fix Access Denied in TreeSize — Identify whether permissions, elevation, encryption, or an unavailable path caused an Access Denied result.
• TreeSize Scan Appears Stuck — Check large file counts, network delay, security software, and inaccessible paths before cancelling a scan.
• TreeSize Is Not Showing All Files — Compare scan scope, filters, permissions, cloud placeholders, and protected content when files appear missing.
• Folder Size Does Not Match File Explorer — Explain size differences caused by permissions, hard links, allocation, cloud files, and timing.
• TreeSize Does Not Open on Windows — Work through installation integrity, Windows security, user profile, and compatibility checks when TreeSize will not launch.
• TreeSize Crashes During a Scan — Narrow crashes to a path, file count, system condition, security conflict, or outdated program build.
• Network Drive Is Not Visible in TreeSize — Check mapping context, credentials, elevation, and UNC access when a network drive is missing.
• TreeSize Results Are Not Refreshing — Refresh or rescan changed folders and understand why a previous result is only a point-in-time snapshot.
• TreeSize High CPU or Disk Usage — Evaluate temporary scan load, antivirus interaction, storage speed, and scan scope before assuming a fault.

• TreeSize vs WizTree for Windows — Compare scan approach, interface, reporting, and use cases without treating one tool as best for every user.
• TreeSize vs WinDirStat — Compare two established Windows disk analyzers by workflow, visualization, portability, and reporting needs.
• TreeSize vs SpaceSniffer — Compare hierarchical tables with a treemap-first disk analysis workflow.
• TreeSize vs DiskSavvy — Compare desktop disk analysis, classification, reports, and network-oriented workflows.
• TreeSize vs Folder Size Tools — Compare a full disk analyzer with simpler folder-size utilities and File Explorer extensions.
• TreeSize vs Windows Storage Sense — Separate analysis and visualization from automated Windows cleanup and maintenance.
• TreeSize Free vs Professional Trial — Understand the difference between an ongoing free edition and time-limited access to paid features.
• Disk Space Analyzer Features That Matter — Use a task-based checklist to compare Windows storage analyzers without relying on feature-count marketing.