Upgrade, DB Loss phobia (Newbie)

[shayanbahal]

Hi
I tried to be as more detailed as i could in the title.
i have a forum with about 2500 members and i really need everything to go great through the upgrade.
I was using the NULL 3.6.8 of vBulletin but i just bought a license (3.7.3).
so the fear of losing the db wont let me start the upgrade.
please advice me through the process and what should I do to prevent this?
will the default upgrade script work without anything to do with the databases?
thanks

[Steve Machol]

Please follow the upgrade documentation here:

http://www.vbulletin.com/docs/html/upgrade/

[shayanbahal]

I was following the link below:

http://www.vbulletin.com/docs/html/upgrade/

but after a uploaded "forums" and i got through the license check of the upgrade.php i get to this page:
-----------------------------------------------------------------
Step 1) Miscellaneous table alterations 1/4

* Altering moderatorlog Table (1 of 1)
* Altering reputation Table (1 of 1)
* Altering usergroupleader Table (1 of 1)
Database Error Database error
The انجمن تخصصی آیفون database has encountered a problem.
-------------------------
Database error in vBulletin 3.0.1:

Invalid SQL:
ALTER TABLE mst_usergroupleader ADD index ugl (userid, usergroupid);

MySQL Error : Duplicate key name 'ugl'
Error Number : 1061
Request Date : Friday, October 24th 2008 @ 01:53:53 AM
Error Date : Friday, October 24th 2008 @ 01:53:54 AM
Script : http://XXXXXXX/forums/install/upgrade_302.php?step=1
Referrer : http://XXXXXXX/forums/install/upgrade_302.php?step=1
IP Address : XX.XX.XXX.XXX
Username :
Classname : vB_Database
MySQL Version : 5.0.51a-community
---------------------------------------------------------------------------

I need your help for this upgrade, i cant let my forum be down for some more days.
and i really need my databases they're everything i have for the forum.
how can i convert the databases? should this be done or is there any other way for this?

[shayanbahal]

I read the php for each update and did the right thing to the database to get the upgrade going!
also we had lots of duplicates in the DB so I had to remove them with bare hands!

thanks though