Grant cannot adding a new user. Please help

[Rachman M Heryanto]

Dear all,

I've a problem using grant. MySQL version 5.0.18-nt (for windows) installed on xp pro.
I want to another host can connect to mysql server in the server computer.

c:\program files\mysql\mysql server 5.0\>mysql -uroot mysql
...
mysql>grant all privileges on *.* to root@'myhost' identified by 'mypass' with grant option;
ERROR 1133 (42000): Can't find any matching row in the user table

trying other :
mysql> insert into user values ('myhost', 'root', password('mypass'),
-> 'y','y','y','y','y','y','y','y','y','y','y','y','y','y');
ERROR 1136 (21S01): Column count doesn't match value count at row 1

once again:
mysql> insert into user(host,user,password) values('myhost','root',password('mypass'));
ERROR 1364 (HY000): Field 'ssl_cipher' doesn't have a default value

mysql> \s
-----------------
mysql Ver 14.12 Distrib 5.0.18, for Win32 (ia32)

Connection id: 49
Current database: mysql
Current user: root@localhost
SSL: not in use <--- I'm not use a SSL
Using delimiter: ;
...
...


How can i resolve this problem..... ??? Please help
Thanks