Say you want to use a single EFS certificate on all of your computers to help eliminate the problem of transferring files across multiple machines. You can use the automatic certificate method that happens the first time you encrypt a file but that certificate will have a pre-determined common name and issuer. If you want to create an EFS certificate with custom information you can use the following syntax:

makecert -n "CN=Test EFS Cert" -pe -ss my -sky exchange -m 96 -r -a sha1 -eku 1.3.6.1.4.1.311.10.3.4