Upgrading Drupal

Hi there,
It is possible to upgrade Drupal version 7.12 to 7.34 ?
Thanks

Hello:
I have installed Mediafront for play videos from Youtube. It was working perfectly but one month about I can't play videos from tablets and smartphones, but with computers I can see videos.
I have updated Mediafront with new version: 7.x-2.2+35-dev and don't work.
Can you guide me please?

I recently took over a Drupal site that is a low 7.x version and has several out of date modules. The trick here is that there are broken/missing core files, but the sites folder is fine. I have a copy of the database from backup & migrate weekly backups.

Please check the steps I am trying to use to do this upgrade:

I wanted to designate that I'm not a complete newbie, because I first started working with Drupal in 2003. I have developed a handful of sites over the years. But it has been almost four years since I have looked at Drupal or done any kind of web development!

But now I am back and I am about to embark on major web development because I'll be developing 10+ personal and business web sites for myself over the next 1 - 2 months. Thus, I am by no means an expert with Drupal, but I have the basic idea about Drupal from using it in the past.

Hello everyone, I hope you are all doing well.

I have been pulled onto a project to re-theme a drupal 3.5.
Knowing how old this version is, I strongly would like to suggest that the client update to the latest version.

So I have a couple of questions for you fine folks.

I have a working drupal 7 site (and a local development test site) and I am planning to upgrade this site to Drupal 8.
All the modules I've used are standard modules I did n't alter or write any own module.

Where can I find a upgrade or installation guide to get this done.

I am working with the stanford Open Framework theme, so Bootstrap and JQuery should be available in Drupal 8, or maybe I Can get things working with the default drupal 8 themes.