Adding an account password

My Windows 7 account has been set up without a password. If I try to add one, there are warning messages that I may lose stored passwords and something called EFS.
Can I ignore these and add a password to the account?

That is the Encrpyting File System. Its up to you, but little loss. Add the password if you like.

Thanks Richard
I've not marked any files for encryption so that should be okay.