After spending 6 hours troubleshooting, I finally found a solution that worked for my Garmin Descent Mk3i. Here’s what I did:
please pay attention to every single detail

Steps to Fix the Boot Loop:

1️⃣ Close Garmin Express:

• Make sure Garmin Express is completely closed on your PC.
• Check the Task Manager and end any background processes related to it.

2️⃣ Turn Off the Watch Properly:

• Hold the Light button until the Garmin triangle logo appears and disappears 2-3 times.
• The moment the triangle appears again, hold the Light button instantly and keep holding until the triangle disappears.
• Let go immediately after it disappears. If the watch stays off, you did it correctly.

⚠️ Don't move to Step 3 until Step 2 is fully completed! (Also, read Steps 3 & 4 before proceeding, as you’ll need to act quickly.)

3️⃣ Connect to PC & Enter Recovery Mode:

• Plug the watch into your PC (Windows) using the charging cable.
• As soon as the boot loop starts, immediately hold the Light button (within the first second) until the triangle disappears.
• Timing is critical—if needed, get someone to help you press the button instantly after plugging it in.

4️⃣ Access Device Storage:

• The moment the screen goes dark, release the Light button and instantly hold the Start/Stop button.
• Keep holding until the Garmin triangle appears again.
• Continue holding until your PC recognizes the watch and you can access its files.
• (I struggled with this for hours until my brother helped by pressing one button while I pressed the other—timing is everything!)

5️⃣ Delete the Problematic Folder:

• Open the Garmin folder on your PC.
• Delete the RemoteSW folder.

6️⃣ Unplug & Reboot:

• Disconnect the watch and turn it on.
• It should now boot normally! You’ll just need to set up a few things again, like when you first turned it on.

This worked for me after hours of frustration—hope it helps someone else! Let me know if you have any questions. 💪

if you need any extra help feel free to contact me on discord on : Dontolidos and i'll be more than eager to help any of you

https://preview.redd.it/as80aq6giufe1.jpg?width=900&format=pjpg&auto=webp&s=d23919ad18e58f9b7da13d424ec9c3a7bd7a6659