shared accounts are frowned upon, or flat disallowed by most security standards - you should be using a unique account for every individual so you maintain auditability.
Thanks for your answer.
I understand that point, but I though that the group users are exatcly for this situation.
If you add the domain admins to every machine (or an appropriate group of trusted people), then they will be able to login to every machine. No need to use some fixed account which everyone knows the password to.
OK. I will try this.