A Sticky Note missing from the desktop may be closed or associated with another account. Start with the Notes list and account before attempting local-data recovery. Microsoft describes note deletion as permanent in Sticky Notes; closing and deleting are different actions, and synchronization is not a versioned backup.

Reopen a closed note
In Windows Sticky Notes, open the ellipsis menu on a visible note and choose Notes list. Search for a distinctive word and reopen the matching note. For Sticky Notes 3.0 and later on Windows 10, the close X closes the note rather than deleting it. It remains in the list.
If no note is visible, launch Sticky Notes from Start and inspect its list. Do not clear app storage or reset the app simply because the desktop looks empty; identify the remaining data first.
Check the identity that owns the notes
Open settings and verify the signed-in account. Personal and work accounts can have different notes. Check an authorized second device or notes surface linked to the same account; if a missing note remains visible there, preserve its text before changes synchronize a deletion.
When synchronization failed, inspect account and app status first. Microsoft’s Sticky Notes troubleshooting guide explains the Notes list, account/sync checks and organizational mailbox requirements. Follow controls in the installed version rather than repeatedly signing out and resetting it.
A note was actually deleted
Microsoft’s documented position is that note deletion cannot be undone in Sticky Notes. An independent copy, screenshot, export or organization’s retained mailbox backup may preserve information, but none is guaranteed because synchronization had been enabled.
If another device might hold an unsynchronized copy, keep it from applying new sync changes while preserving visible content. Do not replace the only remaining note while resolving a synchronization conflict. Ask the administrator which retention policies apply to an organizational account.
What local files can establish
Sticky Notes application data is tied to the Windows account and app version. A local database copy, where present, is not an ordinary text note and may require companion database state. Before resetting the app, preserve relevant user-profile/app data through an appropriate backup process; verify the installation’s data location rather than overwriting a database path from another version.
XRecovery can search readable storage for remaining files. A recovered Sticky Notes database is a candidate to preserve and inspect, not proof that the missing note can be restored.
Verify the information
Compare the exact text, task details and embedded images you require. Save a separate usable copy. For future deletion prevention, enable Confirm before deleting in Sticky Notes settings. Keep independent copies of important notes; synchronized current state alone is not recovery history.
For the next step, see Document Recovery: Deleted, Unsaved, Overwritten or Damaged?.