You do not have the rights to perform this operation configure single sign on (SSO)

you receive: You do not have the rights to perform this operation configure single sign on while configuring Single Sign-On services on sharepoint 2007

solution:

1.Be sure that you are logged on "Manage Settings for Single Sign-On" under operations using the same domain\username that you specified to run the service "Microsoft Single Sign-On" under windows services.
2. The administrator account that used to manage "Single Sign-On" service and the enterprise administrator accounts must match the account that used to run "Microsoft Single Sign-On" service under windows services.