The computer I was using which is the one I used to sign the Ubuntu code of conduct got a hardware problem and I lost it. If I want to continue my work on launchpad, how can I proceed to recover, recreate or reset the whole process so that I can relate my PC again to launchpad with the PGP?
Launchpad Recovery YourAccount/ImportingYourPGPKey
Renewing your key
You may have set your key to expire. You can update your key's expiration date and republish it.
Step 1: Open Passwords and Encryption Keys.
Step 2: Select the My Personal Keys tab, select your key and open the property window by pressing Space Bar or double clicking with your pointer. Select the Details tab of the property window.
Step 3: Set a new expiration date or choose never. Close the property window
Step 4: With you key still selected, select Remote > Sync and Publish Keys from the menu. Choose the Sync button.
review the source https://help.launchpad.net/YourAccount/ImportingYourPGPKey
Launchpad allows you to continue working with more than one PGP key associated with your account. All is not necessarily lost just because you lost one of your PGP keys; as long as you are using one of your authorized PGP keys, you can continue to sign stuff.
In Launchpad, under your account settings, go to "Change your OpenPGP keys" page, and use the Import Key functionality to import another key. And this time, don't lose it.
If you have data encrypted with your original PGP key that can only be decrypted using that key, then you are out of luck for obtaining that information. But you won't lose your Ubuntu Code of Conduct signature by adding more PGP keys to your Launchpad profile.