If a firmware update is interrupted, keep the review factual: power state, app prompt, device screen, and the next stable entry. The goal is a clear recovery path, not a dramatic conclusion from one interruption.

Record the power state
Write whether the device stayed connected, the computer stayed on, and what the screen showed. Keep this as an observation, not a device judgment.
Read the app prompt again
After reopening Ledger Wallet, record the prompt or version state. If app entry is unclear, return to Ledger Wallet Download and Installation Guide.
Check the connection layer
If the device is not recognized after interruption, review cable and permission state one layer at a time. Use Why Ledger Will Not Connect to a PC as the order.
Continue from a known state
The next step should begin from the visible app prompt and device screen, not from repeated random attempts.