Find large files.
Understand your drive.

Choose the location

Open File Explorer → This PC and record the free space on the affected drive. Inspect that drive or one known personal folder first. A scan of C: does not explain usage on an external drive or a network share.

Windows Settings → System → Storage gives a category-level starting point. In a personal folder, File Explorer’s Details view lets you sort files by Size. Folder totals require a separate calculation; the absence of a size in a folder row is not proof that the folder is empty.

Read three different numbers

File size

The logical length of the file’s contents.

Allocated space

The storage actually allocated locally. Compression, sparse files and online-only placeholders can make it differ from logical size.

Drive free space

The outcome you care about after an action. Snapshots, open files, provider behavior and activity elsewhere can affect the change.

Do not add the largest rows and promise that total as recoverable space. The inspection may have skipped inaccessible locations, and several names can refer to shared file content.

Make a useful shortlist

1. Group by purpose. Separate exports, installers, backups, recordings and application-managed data. The same extension can serve different purposes.
2. Check dependencies. An old project asset may still be linked from a document or editor. A backup may be your only independent copy.
3. Choose the smallest action. Retain, move a verified copy to another drive, use a provider’s local-space control, or review removal.

Do not manually remove Windows DLLs, the installer store or application databases because they appear large. Use the owning Windows or application maintenance workflow.

Inspect in WhimRoom

In My space, choose the affected location and inspect it. Use the storage breakdown and file observations to narrow the review. Check scope, skipped locations and errors before interpreting totals. Inspection is separate from approval to change files.

For a candidate you want to keep elsewhere, use a copy workflow with a separate destination and inspect the result. For possible duplicates, compare contents rather than relying on matching names or dates. A target such as 10 GB remains a goal until eligible files have been reviewed.

Check the result

Read the drive’s free space again after the selected operation finishes. Keep the before/after values and the operation result. If the numbers differ from expectations, check the Recycle Bin, pending cloud activity and reported failures before selecting more data.

For temporary-file cleanup, follow the separate full-drive guide. For repeated content, use duplicate review.