Quick answer: Thumbnail cache is generally safe to delete. Windows will rebuild thumbnails when folders are opened again.
Why this uses C drive space
Windows stores thumbnail previews for images, videos, and documents. The cache can become stale or consume space over time.
Safe cleanup steps
- Use Disk Cleanup or Temporary files settings.
- Select Thumbnails if available.
- Close File Explorer windows for best results.
- Delete and let Windows rebuild thumbnails.
- Expect folders to load previews more slowly once.
What to avoid
Do not delete original photos or videos when you only intend to clear thumbnail cache.
How DiskTidy helps
DiskTidy can help you review temporary files, browser cache, cleanup candidates, and large files before deleting anything. It is designed for local, review-first cleanup instead of blind one-click deletion.