Upgrading Drupal

i have this user waning in admin/build/themes

Could someone please tell me why I am unable to upgrade from 6.6 to 6.10? Here's what I have tried several times:
I put my drupal site in offline mode
After downloading 6.10 to my computer desktop, I upload 6.10 to my drupal site's directory (I go to my host server control panel, then to the file manager (host server is hostmonster.com if it matters), and I extract 6.10
I go back to my drupal site and run update.php
When the "Drupal database update" screen appears, and I click the "select versions" button, every single module says "No Update Available."

I set up my Drupal site on 1/23/09, so when I started getting dire warnings about an urgent security upgrade a month later, I was both annoyed and concerned. Annoyed at having to do what seemed like a total re-install when I'd just gotten my new site customized the way I wanted it, and concerned about the potential to totally screw up my site in the upgrade process.

Most of the info I found here about how to streamline the process requires the site admin to write scripts or run them, and this won't work for me since I don't know anything about Linux commands and don't have easy access to run scripts against my server anyway.

Furthermore, while I've always been a stickler for maintaining a separate development environment when building or maintaining programs or web applications, with Drupal it seems like more trouble than it's worth since the 'bones' of the site don't tend to change much once you're done installing and customizing your site. All the content of the site (i.e., articles, forum posts, member profile data, etc.) is stored in the site database, and I don't feel I need a 'development' copy of the database because its structure rarely changes, too. I backup regularly, but that's about it.

in upgrading from ver 5 to ver 6 i run the update.php
then the following user warining resulted.

user warning: Duplicate entry '2262-0' for key 1 query: ALTER TABLE locales_target ADD PRIMARY KEY (language, lid, plural) in /home3/mysite/public_html/areatopic/includes/database.mysql-common.inc on line 374.

what am i supposed to do?

appreciate support in advance.

Kenji

I'm trying to solve a problem with my theme templates. I'm upgrading from Drupal 5 to 6 and porting over my theme at the same time.

Normally, changes to node.tpl.php take effect right away once the theme registry has been updated. In my case, the node.tpl.php file takes proper overrides over the nodes EXCEPT for blog nodes (created from the core blog module). The blog nodes all default to the core>modules>node>node.tpl.php file no matter what I do.

However, when I create a node-blog.tpl.php the blog nodes are properly effected.

I've volunteered to upgrade an old site. I managed to upgrade from 4.7.4 to 4.7.11, and from 4.7.11 to 5.16. But when I try to upgrade from 5.16 to 6.10, update.php runs for a loooong time (approx 5 minutes), and finally results in

An unrecoverable error has occurred. You can find the error message below. It is advised to copy it to the clipboard for reference.
Please continue to the error page
An error occurred. http://bil.skurker.net/update.php?id=1&op=do

The error page says

Drupal database update

The update process was aborted prematurely while running update #6000 in system.module. All errors have been logged.

Going to the admin interface, I get

One or more problems were detected with your Drupal installation. Check the status report for more information.

The status report tells me

Database updates Out of date
Some modules have database schema updates to install. You should run the database update script immediately.

Rinse and repeat...

Looking at the database, I see that some tables have been added, but not all that should be in a 6.x install.