Here are some common places to look for your downloaded ebook:

1. Default Download Folder: Check your device's default download folder, usually labeled "Downloads".

2. Cloud Storage: If you use cloud storage services like Google Drive, Dropbox, or OneDrive, search for the ebook in your files there.

3. Ebook Reader App: If you use an ebook reader app like Kindle, Adobe Acrobat Reader, or Nook, check your library section within the app.

4. Browser Download History: Your browser's download history can show you where the ebook was saved.

5. Search Your Device: Use your device's search function to search for the ebook by title, author, or file type (e.g., .pdf, .epub, .mobi).

If you still can't find it, try these tips:

1. Check your email: If you downloaded the ebook from an email, check your inbox and spam folder.

2. Re-download the ebook: If possible, try downloading the ebook again.

3. Contact the source: If you downloaded the ebook from a website or online store, contact their customer support for assistance.

By following these steps, you should be able to locate your downloaded ebook.