I am using EFS to encrypt some files on a windows 7 ultimate x64 machine. I have two different EFS certificates, one on a smartcard and another on the PC. I know that i can change the EFS certificate used by windows to encrypt files and folders following the procedure described at http://windows.microsoft.com/is-IS/windows7/Change-the-key-you-use-to-encrypt-files-and-folders What i need is to encrypt only some specific files using the certificate stored on my smartcard without having to follow the above procedure to set the smartcard certificate as the one used by default in windows to encrypt files and folders, this in order to avoid to follow the procedure each time i want to encrypt some new specific file using the smartcard certificate and to go back with the same procedure to use the PC stored certificate for encrypting other files. Is there any way to encrypt a file choosing a specific key among multiple ones? Thanks a lot Michele

Actually the certificate is based on the logged on user account and password. If you want to change a certificate, you can try to encrypt after logging in with another user account. However you must create certificates for this user account in your smartcard.

Thanks Arthur, unless using cryptoApi to encrypt a file with a specific key, your suggestion seems to be the only workaround. Michele