Locked All the Users in One Client and Log-Off

I locked all the users in one client and log-off from sap. Now, how can I connect to sap?

I never face the same situation but following may be a soluton:

If the system has been locked using TP.exe then open it with following steps .

1. login as adm os user
2. open a command prompt
3.run following command -> tp.exe unlocksys pf=

else

You can connect using sap* user.

First Check that following parameter values shold be
1. login/no_automatic_user_sapstar should be 0.
2. Login/failed_user_auto_unlock should be 1.

You can check/add both parameters at OS level checking profiles files. Restart the system if you made any changes .

Then login into SAP System as adm user and open a SQL prompt .

Execute following sql update command:

alter table sap.usr02 set bname='sap**' where bname='sap*' and MANDT='' ; commit;

then you can login as ,sap*,pass into your system and unlocked all user

PS:
As far as I know both command will not harm system if execuated in a proper way.