Upgrading Drupal

hi ,
being new to drupal i wanted to update drupal 5 contributed modules to drupal6. i upgraded my drupal core modules to drupal 6 using the convetional ways posted in the site..but i am finding it difficult to upgrade some contributed modules to drupal 6 as they have became obsolute. so i am confused what to do... plz suggest me what all measures i have to take to upgrade those modules to drupal 6.plz help me out from this situation...

thanks in advance,
Vilash.

After upgrading from 6.2 to 7 I ran update.php and got

DatabaseSchemaObjectExistsException: Table role_permission already exists. in DatabaseSchema->createTable() (line 630 of MySite/public_html/includes/database/schema.inc).

The website encountered an unexpected error. Please try again later.

Uncaught exception thrown in session handler.
PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'ssid' in 'where clause': SELECT 1 AS expression FROM {sessions} sessions WHERE ( (sid = :db_condition_placeholder_0) AND (ssid = :db_condition_placeholder_1) ) FOR UPDATE; Array ( [:db_condition_placeholder_0] => a69f0d6c547eeb42adad76c477888932 [:db_condition_placeholder_1] => ) in _drupal_session_write() (line 204 of MySite/public_html/includes/session.inc).

Hm .. maybe the database hadn't been finished its update yet?
So I waited for about a quarter of an hour and ran update.php again and got

DatabaseSchemaObjectExistsException: Cannot add index system_list to table system: index already exists. in DatabaseSchema_mysql->addIndex() (line 433 of MySite/public_html/includes/database/mysql/schema.inc).

The website encountered an unexpected error. Please try again later.

Hi all, is there an alternative of Nodewords for Drupal 7 ? it looks like Nodewords is replaced by Meta tags but there is not yet a distribution for it.
So, how can i manage my seo info in Drupal 7 (description, meta keywords, ...) ?

Thanks,
Christophe

I have the issue with drupal after upgrade it from '.17 to '.20. So, basically when I try to edit any existing content, getting this message "The username admin does not exist." If i try to to so as another user getting the same problem. I think that there is problem with mysql db after upgrade. But I got lost... Is anyone experienced this issue...? If so and there is a solution please, share it.
PS: I did check Permissions, Performance, update mysql db (Mysql 5.5.8 on FreeBSD 8.1), rebuilt content permissions. But the problem still there.
Thanks in advance, Ross

I have a drupal 6.20 multisite & want to upgrade to drupal 7.0. I'm running on ubuntu hardy. My mysql & php versions are suitable. I've uncompressed drupal 7, and copied into it my old 'sites' folder. If I go to site/upgrade.php I get:

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