Problem with 3.6.8 to 3.7.4 update

[yeku]

I uploaded the files of the update and I try to update this error:

Database error in vBulletin 3.6.8:

Invalid SQL:
ALTER TABLE userlist ADD friend ENUM('yes', 'no', 'pending', 'denied') NOT NULL DEFAULT 'no';

MySQL Error : Table 'forolechuzo.userlist' doesn't exist
Error Number : 1146
Request Date : Saturday, January 24th 2009 @ 03:03:53 AM
Error Date : Saturday, January 24th 2009 @ 03:03:53 AM
Script : http://www.lechuzo.com/install/upgrade_370b2.php?step=3
Referrer :
IP Address : xxxxxxxxxxxx
Username :
Classname : vB_Database
MySQL Version : 5.0.45

I can not go to my admincp, any idea?

thanks