You are confusing several different things.
B4i creates a keystore and a csr file.
Using this csr file you create certificates.
It is highly recommended to always use the same csr file. If you changed it then you need to delete all other certificates and provision profiles and create new ones.
Moving between computers is easy. Copy the complete keys folder to the new computer and set the password (Tools - Private Sign Key - Set Password). Don't create a new keystore + csr file.
If you are unable to solve it then delete all files, revoke the certificates and provision profiles and start from scratch.