When you attempt to decrypt a file or email, you receive the error message:
It is not possible to decrypt this message because your keyring does not contain usable private key(s)...
The underlying cause of this error message is that Encryption Desktop (previously PGP Desktop) does not have access to the private key needed for decryption. This could be due to any of the following:
The sender simply encrypted the file or email using the wrong public key
You have not properly transferred your private key or keyrings from another computer
You have deleted or lost the private key needed for decryption
This article describes several common scenarios in which this error might occur, and points to other answers that provide possible resolutions. To begin, you should determine whether Encryption Desktop actually has your keypair. This can be done by just looking at your key's icon.
Click the PGP Tray lock icon in your system tray and then click Open Encryption Desktop:
Click PGP Keys in the control box.
Select the keyring that contains your key:
Now locate your key inside the window on the right. Based on your key's icon, complete either of the steps below.
If your key's icon is a pair of keys, then Encryption Desktop does have your keypair, and the error is likely occurring because the sender simply used the wrong public key during encryption. In this case, the resolution is simple: make your current public key available to the sender, then ask them to re-encrypt and re-send the file/email to you. If you suspect that the sender encrypted to the wrong public key, please refer to the following tutorial answers about ways to make your public key available to others:
If your key's icon is just a single key, or you cannot locate your key at all, then Encryption Desktop does not have your keypair. In this case, you should consider the following common scenarios and refer to the appropriate knowledge base answer(s) for more assistance: