Free Up Disk Space on a Windows Workstation

Windows shows a low-disk warning when the system drive (usually C:) drops below roughly 10% free. Once free space falls under ~1-2 GB, Windows Update may fail, applications crash on save, temp files can't be written, and user productivity grinds to a halt. This recipe walks through the standard triage: identify what is consuming space, safely remove known-disposable data, and leave the workstation in a healthy state without touching user documents.

Run this when a user reports a "Low Disk Space" toast, a red bar on the C: drive in File Explorer, application errors such as "There is not enough space on the disk", or OneDrive/Teams sync failures caused by the local cache running out of room.

• The system drive has at least 15-20% free space restored.
• Temporary files, Windows Update caches, old Windows installations, and Recycle Bin contents are cleared.
• Top space consumers are identified so you know whether this is a recurring problem (e.g., oversized OneDrive cache, bloated user profile, large Downloads folder).
• User data (Documents, Desktop, Pictures, Outlook OST within reason) is left intact.
• Storage Sense is enabled so the machine self-maintains going forward.

Do not blindly delete

• Never delete from C:\Users\<name>\ directly without confirming with the user — Documents, Desktop, and Downloads often contain the only copy of important files.
• Outlook OST files (in %LocalAppData%\Microsoft\Outlook) can be several GB. Deleting them forces a full resync which is fine on a fast connection but painful on remote/VPN users.
• OneDrive/SharePoint cached files: use "Free up space" from the OneDrive context menu rather than deleting the folder.
• Windows.old can only be removed within 10 days of a feature update — after that Windows cleans it automatically. Do not force-delete it during that window or rollback becomes impossible.
• Hibernation file (hiberfil.sys) can be large. Only disable hibernation on desktops; on laptops it breaks fast startup and hybrid sleep.
• Pagefile — do not delete or disable unless you know the machine has adequate RAM and you understand the impact on crash dumps.

Compliance

On managed/regulated endpoints, check whether your DLP or eDiscovery policies require preservation of temp files or browser caches before running cleanup.