I re-imported the PGP key into new system install. Now when I try to decrypt my backup text file, Ubuntu warns me
Decryption Failed. You probably do not have the decryption key.
Please help, I am new to Ubuntu.
Missing Private Keys
GnuPG cannot find your private key, at least not the one for decrypting.
It will include more detailed information on your key. Is there a subkey whose line is ending with "E" for encryption?
If that fails, make sure once again you imported to the right key ring (each user has it's own, and you could add another keyring if you want somewhere else -- most easy way would be to import the key again.
If this also fails, you probably didn't export the private keys. Try to look at the headers of the exported file, if it is ascii-armored, you should read something like
If you only exported the public key, you will read
How to Recover My Secret Keys?
You cannot recalculate them from your public keys. If you could, everybody would be able to!
Surely you've got a backup of your old user folder. Recover it somewhere and use
If you haven't got the key any more, you should send your revocation certificate to the keyservers now. Now the keyservers say you're not using that key any more and you can create a new one without old "garbage" on the keyservers.
If you haven't got a revocation certificate, you will not be able to erase that key from the keyservers.