How do I install 5.1 (upgrade to it) safely?

How do I install 5.1 (upgrade to it) safely? I have on the same server 4 websites running on version 3.7. They are current functional websites. I also have one site in version 5. That is the one I need to upgrade to version 5.1. When I clicked on version 5.1, it says that it has detected the previous versions of the site. How do I make sure that only version 5 site gets upgraded?

"When I clicked on version 5.1" - if you are talking about the .msi you downloaded, then it is referring to a previous version of the ProjectManager etc being installed on your PC - usually located in x:\Program Files (x86)\telerik\Sitefinity x.x\etc  or some similar program-installation location - it's not looking for any running websites.

As previously, it's the ProjectManager (once installed) that does the site upgrade process, and which lets you see all the projects and choose which to upgrade - it gets the list from your Projects.xml file in the afore-mentioned location.

P.S. Telerik have updated the current download files to 5.1.3210.0  which is the 5.1-hotfix and on the off-chance you were an early downloader of 5.1.3200.00  (as I was) then I'd recommend you re-download and upgrade using the hotfix version rather than the original 5.1 release. Either way, make sure you have backups of everything... just in case there is a breaking change and you need to roll back.

I downloaded 5.1.3210.0 msi file. I saved it and installed on my D: drive. I see the project manager is offering me to either create a new project or import some other one. I have on the same drive a project sitting - version 5.0. How do I upgrade it to version 5.1.3210? The new project manager does not have a list of project for me to chose for the upgrade. It's blank.

As mentioned, the ProjectManager gets the list of projects from the projects.xml file, not by scanning your disk or anything like that.

Unfortunately, the install doesn't appear to copy this from the previous version's installation folder, so you may need to go to your 5.0 installation folder (which should still be there) and copy it to your new 5.1 installation folder... then projectmanager should list all the previous projects and their versions.

@Inna
  The safest thing to do version to version is to not click the msi download, but instead to click the link that says all files.  Then in there you can download JUST the projectmanager executable (Sitefinity.exe)...then just overwrite the old file with the new one.  It'll fire up like always reading the xml file @MB mentioned, and give you the upgrade option on the projects.  Instead of now where it probably installed to a new folder thus giving you a new blank projects file.

Much of a muchness really - just depends on your preferences.

The msi doesn't do all that much - installs the new version (and any new documentation) into a new folder, updates the various menu links to use the new version-folder, and deletes the old version of projectmanager from the old version-folder.

It leaves behind everything else of the old version, which I find useful for comparing the _EmptyProject folders, to see the changes between versions.

However, it would just be nice if the msi would copy the projects.xml to the new version-folder at the same time as it deletes sitefinity.exe from the old version-folder... but that's a trivial task to do manually.

Yeah +10 on the projects xml either being copied over or stored in a more common place

Ok, I migrated a projects.xml file from the Sitefinity_Project_Manager_5.0.2800.0 to the new one: ProjectManager_5.1.3210.0
Then I realized that I moved the site that I'm working on (the one I migrated from 3.7 into 5) to a different directory. So, for the site to be recognized by 5.1, I renamed the directory to one listed in the projects.xml file. I opened my project with ProjectManager_5.1.3210.0 and nothing happened - the project is still in version 5. - see image attached: it shows that I opened the site in proj manager 5.1, but the site is still in version 5. I searched online and found this link: www.sitefinity.com/.../. There are instructions on this page:
4. Select the project which you want to upgrade and click Upgrade button.
The selected project is upgraded to the latest version of Sitefinity Project Manager.

I do not see the "Upgrade button" anywhere. Is it suppose to be THAT PAINFUL to upgrade or am I doing something wrong again???

Right-click on the project in the list?  Should see upgrade...or is it also under actions?

(You can also just edit the projects.xml directories instead of screwing with your file system btw...its just a pointer to the project)

I did every  click imaginable - there is no button. Here are the two files that show what I see when I right click on the project and when I click on Actions

What if you blank our your peoject.xml file, then load the project in with the IMPORT button there at the top?

Steve, some magic has happened: I renamed the site folder to what I used to be before I tried to upgrade, changed the name of the folder in xml file, as you've recommended, and I got a whole new bunch of new options in the "Actions" drop-down, including the "Upgrade" one. I clicked on it and it shows life. I see this:

Your site will be running faster

Oh good, let that run, it wont take 2 hours :)  I haven't had it take more than 30 seconds (assuming you have a med-small site?)

wow, looks like it's rolling full speed ahead... do i need to do anything else? (e.g. compare files, change something...) i mean to complete the upgrade

Nope, click the upgrade button then load the site to auto-apply the update.  Only thing to do after is test your pages if you have any custom controls...

That's why (when it works) the project manager is the best way to upgrade...3.7 was a pain in the ASS! :)

true - about 3.7.

So long as you have backups of everything - and I do mean EVERYTHING - then after some experimenting with this stuff (and a few screw-ups later) I found that I basically understood the process and what were the key elements and triggers... and I ***MUCH*** prefer this to even the simplest upgrade of a V3 site.

I remember upgrading customer's 3.x sites and having a stupidly long list of 'steps' I needed to remember... and still never being comfortable that it was 'right'... always half-expecting them to find something I'd missed.