Clean Windows C Drive

Clean Windows C Drive

Objective

Assess C: health, diagnose usage, separate safe cleanup from review-only data, and preserve normal Windows operation. Prefer Windows-supported cleanup mechanisms and reversible actions. Never claim that a single check guarantees future hardware or filesystem health.

Safety rules

• Start read-only. Do not change anything during the audit.
• Run the health gate on every invocation before measuring cleanup candidates.
• Stop cleanup on a Critical result. On Attention, explain the failed checks and clean only if the warning is solely low free space and the proposed action is low risk.
• Read [references/safety-catalog.md](references/safety-catalog.md) before recommending or performing cleanup.
• Never manually delete from Windows, Program Files, ProgramData, System Volume Information, Recovery, Boot, WinSxS, DriverStore, EFI/recovery partitions, registry hives, page files, or restore-point storage.
• Never bulk-clean a user profile, Downloads, Desktop, Documents, cloud folders, browser profiles, mail, projects, VMs, or game libraries.
• Never use registry cleaners, broad wildcards, recursive deletion from a drive root, DISM /ResetBase, ownership changes, ACL changes, or unresolved environment variables.
• Do not disable hibernation, System Restore, Windows Update, antivirus, indexing, reserved storage, or OneDrive Files On-Demand merely to gain space.
• Prefer Windows-supported cleanup and reversible actions. State when recovery is impossible.
• Verify exact resolved targets stay inside each user-approved location before a destructive operation.
• Never move installed-program directories, AppData, ProgramData, game libraries, cloud placeholders, shortcuts, profile configuration, WSL/Docker/VM data, or any folder tree with the generic relocation script.

Workflow

1. Establish scope

Confirm Windows and C: are the intended targets. Determine whether the request is audit-only, recommendations, or cleanup after approval. A general "clean C:" request authorizes an audit and plan, not unspecified deletion.

2. Run the automatic health gate

Run the bundled read-only health check on every invocation:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\Test-CDriveHealth.ps1"

Read [references/health-policy.md](references/health-policy.md) when interpreting the result. Report Healthy, Attention, Critical, or Unknown with the individual checks. Treat inaccessible checks as unknown, not healthy. Do not repair filesystems, change BitLocker, run offline CHKDSK, update firmware, or modify storage settings without separate approval.

This health gate is automatic when the skill is invoked. Do not create a scheduled task, reminder, or background monitor unless the user explicitly requests recurring monitoring.

3. Audit before recommending

Run the bundled read-only report:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\Get-CDriveCleanupReport.ps1"

Use -IncludePersonalFolders only when the user requests measurement of major personal folders. It still changes nothing.

For deeper read-only checks, use:

Get-Volume -DriveLetter C
Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
powercfg.exe /a

Treat all sizes as estimates. Apparent directory size is not safely reclaimable size.

4. Classify findings

Classify every candidate as:

1. Low risk through Windows controls: temporary files, thumbnails, Delivery Optimization cache, DirectX shader cache, and error reports exposed in Windows Storage settings.
2. Conditional: Recycle Bin, Windows.old, update cleanup, driver packages, languages, hibernation, restore points, app caches, dumps, and uninstalling apps. Explain consequences first.
3. User review only: downloads, media, archives, installers, ISOs, VMs, projects, cloud files, browser/mail profiles, and game data.
4. Protected: system and application locations listed in the safety rules.

5. Present the plan

Before changing anything, list each exact category or path, measured size, supported action, side effects, recoverability, administrator need, and restart need. Order lowest risk first. Do not promise all measured bytes are reclaimable.

6. Obtain explicit approval

Ask for approval of exact cleanup groups. Approval for one group applies only to that group. Obtain separate approval for Recycle Bin, personal files, uninstalling apps, hibernation, restore points, or rollback data.

7. Use supported cleanup

For a deep cleanup request, read [references/deep-clean-policy.md](references/deep-clean-policy.md). Preview the fixed deep-safe profile first:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\Invoke-DeepCDriveCleanup.ps1" -Mode Preview -IncludeComponentStore -IncludeDeliveryOptimization

The deep profile covers only regenerable caches and old diagnostic/installer leftovers at exact roots. It detects Chrome and Edge cache-only subdirectories but never touches cookies, passwords, history, sessions, extensions, bookmarks, downloads, or profile databases. Optional component-store and Delivery Optimization cleanup use Windows-supported commands only.

After showing the preview and obtaining explicit approval for the deep profile and each optional Windows action, execute with the exact phrase:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\Invoke-DeepCDriveCleanup.ps1" -Mode Execute -ConfirmPhrase "DEEP CLEAN APPROVED CATEGORIES" -IncludeComponentStore -IncludeDeliveryOptimization

Close browsers first. Skip locked files and optional actions that need unavailable administrator rights. Never interpret “thorough” as permission to delete protected, personal, rollback, recovery, or configuration data.

• For approved low-risk file cleanup, preview with the bundled allowlist cleaner. It only considers files older than the category threshold and changes nothing in Preview mode:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\Invoke-SafeCDriveCleanup.ps1" -Mode Preview -Category UserTemp,CrashDumps

• Show the preview and obtain explicit approval. Execute only the exact approved categories with the required confirmation phrase:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\Invoke-SafeCDriveCleanup.ps1" -Mode Execute -Category UserTemp -ConfirmPhrase "DELETE APPROVED ITEMS"

• Never pass unapproved categories. The cleaner intentionally does not accept arbitrary paths, Windows directories, browser profiles, Downloads, or Recycle Bin.
• Prefer Settings > System > Storage > Temporary files or Storage Sense for Windows-managed categories.
• Prefer an application's own cache or uninstall control.
• For OneDrive, verify sync health and use "Free up space"; do not delete synced files.
• Use Dism.exe /Online /Cleanup-Image /StartComponentCleanup only when analysis recommends it, the user approves, and elevation is available. Never add /ResetBase.
• For user files, operate only on an explicit item list and prefer Recycle Bin or a verified destination on another drive.
• Skip locked or denied files. Do not take ownership or weaken permissions.

8. Relocate ordinary files safely

Read [references/relocation-policy.md](references/relocation-policy.md) before proposing relocation.

Use the manifest planner only for large, old, ordinary files in the current user's Downloads folder. It is read-only except for writing the manifest:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\New-SafeRelocationPlan.ps1" -DestinationRoot "D:\CDriveArchive" -OutputPath ""

Show the exact manifest and obtain approval. Preview it before execution:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\Invoke-SafeFileRelocation.ps1" -ManifestPath "" -Mode Preview

Execute only after approval of that unchanged manifest:

powershell -NoProfile -ExecutionPolicy Bypass -File "\scripts\Invoke-SafeFileRelocation.ps1" -ManifestPath "" -Mode Execute -ConfirmPhrase "MOVE APPROVED FILES"

The executor must copy, verify SHA-256 and size, then delete the original. Never overwrite a destination. If verification or source deletion fails, preserve the source and report the duplicate or partial result.

Move installed apps only through Settings > Apps when the app exposes Move. Move game libraries only through the launcher's supported library feature. Move known folders only through Windows Location properties after separate approval. Never simulate these operations with filesystem moves or junctions.

9. Verify

Re-run Test-CDriveHealth.ps1, re-measure C: free space, report the before/after difference and all skips/failures, confirm Windows Update and Windows Security were not disabled, and report whether restart is pending. Recommend keeping a practical 15-20 GB free buffer without presenting it as a universal requirement.

Response format

For a health or audit request, return overall health, failed/unknown checks, current free space, largest relevant candidates, safe-now recommendations, conditional choices, protected areas, and the exact approval needed next.

For cleanup or relocation, return approved actions performed, free space before and after, copied/verified/deleted counts, duplicates or retained originals, skips/failures, restart requirements, and remaining optional actions. Never claim space was reclaimed after only an estimate, preview, or copy that left the source intact.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: 1181652815-hub
• Source: 1181652815-hub/clean-windows-c-drive-skill
• License: MIT

Install and usage instructions live in the source repository linked above.