Upgrading Drupal

Because of the many errors after I updated from 6.11 to 6.12, I will go back to 6.11. How do I do this? Is it just to overwrite the files and run update.php?
6.12 problem: disappeared books, blocks and some posts are invisible so I can't see them. They are in my database.
Will it be a version 6.13 soon?

After doing the update from Drupal 5.16 to Drupal 5.18, I am unable to fetch data about new releases for anything. Status screen seems to indicate upgrade went well, and no errors were reported.

Here's a list of files changed by the latest Drupal upgrades. We use this so we don't have to replace the entire Drupal installation, as usually only a few specific files have actually changed.

Files Changed by Drupal Upgrades - simply select the list pertaining to your Drupal installation.

Cheers,
Alex

I want to upgrade my sites from their present 5.18 to the latest 6. I have been using filemanager and attachments modules since 4.7 , but these are not good to go for 6 . Am I going to have issues just ignoring them and using the core upload instead after upgrading to 6 ? Should I do anything before upgrading ?
Thanks for any comments/advice

Hello everybody! I'm in desperate need of your help, so please have patience with a geek newbie as I am!! I have to rebuild a site made with drupal last year... now I'm tryin' to work on it, and first thing I want to do is to upgrade it... specifically from v. 6.3 to the latest, 6.12.... but........ I just can't succeed in doing it. I'l try to explain: I'm working on the site in local, this means drupal here is inside xampp/htdocs... so, I unpack the 6.12 files and copy them into the directory called xampp/htdocs/"sitename" ... insiede this same directory there's another one, named drupal 6.3, and so after many many trials I also tried to unpack files in there.... then I load the update page on localhost, and drupal starts the passages allright, but when I get to the page where all possible new updates are displayed the menu behind any object listed is set on "no updates available"....... but on the administrator, reports for the site it still is full of red warning messages, telling me I have to upgrade to recommended version /6.12....... where am I wrong?
I've tried to unpack the files also into backup directories, but obviously it doesn't work.

I'm having a really big issue with upgrading my views module. I'm just learning drupal so forgive me if this is a simple fix, but I am quite a ways into development of my site.

I have been upgraded my drupal installation and have managed to upgrade the drupal core successfully to 6.12. All the other contributed modules I have installed also seem to be working fine and are up-to-date. However when I came to upgrade the Views module and run update.php I am faced with the following error message