I had installed and activated unattended ..., but now this morning the Lubuntu desktop was not reachable thru NoMachine.

I then tried to interrupt the presentation thru the keyboard, but it turned out that the computer was frozen.

Of course, I don't know if this is due to the installation of Nomachine or perhaps due to the updates that were installed (I don't know if updates were installed overnight).
So I have disabled the unattendet for the time.

When I look at the startup folder, there is a file of the PowerPoint that I need to start, but it don't start.

However, I suspect that it would be easier to possibly put a script(like michaelk says) in the startup folder that starts the ppsx file.

Can anyone maybe help me with this? The powerpoint file(powerpoint.ppsx) is on the desktop"

Before uploading, make sure that the presentation is configured to loop:

Slide Show -> Slide Show Settings -> Loop and repeat after

Then you can have a simple shell script and save it in the ~/.config/autostart/ directory which will then start automatically upon login (and if you have autologin after reboot) it will show the slides:

However, if there is a high chance that the presentation ends, you might want to set up some kind of service to monitor the presentation and restart it if it fails. Which distro is this on?

There are several other valid approaches too.

Thanks for this help, monday I will see which distro version it is, because at this moment I cannot reach the system, I must first read more about the settings that I must do to reach the Lubuntu machine over the internet. When I am at the same network, the Lubuntu system is reachable.

You will need to be able to configure the remote router to forward the desired port to the lubuntu PC. Assuming the remote router is using a dynamic public ip address you can use a free dynamic dns service like noip to have a regular URL.

The PowerPoint file now starts automatically.

I have decided not to use "NoMachine", because an extra application has to be installed on the Windows 10 systems.

My new choice fell on the Windows Remote Desktop, I've tried to use the following manual (https://linuxconfig.org/ubuntu-22-04...rom-windows-10), the installation and connection works perfectly, but as soon as I connect, I only see a black screen, does anyone know how I can solve this.

I would like to work with a system that is as clean as possible, which is why I am looking for a program (bootable from a USB stick) that allows me to create an image of the HD of the Ubuntu machine, so that I can restore the clean system after an unsuccessful attempt . Does anyone have a tip for a good ISO for a clone program?

Information about the Lubuntu Version used
-Ubuntu 22.04.3 LTS Jammy
-LXQt Version: 0.17.0

Well, if you were using a Raspberry Pi, you could use Overlay file system, which is read-only.

There might be some tricks you could use in Ubuntu or Linux Mint to switch over to a chroot on a RAM disk.

Or you could try making your own custom Live image:

https://help.ubuntu.com/community/LiveCDCustomization

For the image I've used RescueZilla, works really great.

Yesterday I've tried to connect to the Lubuntu PC from home thru Remote Desktop, the connection worked, but as I already mentioned I only saw a Desktop. I've then tried to create a text file on the Desktop, which worked.

However, this morning I saw that the Lubuntu-computer was frozen. I then checked (after a restart) whether the text file was indeed on the Lubuntu PC, which was successful.

Maybe I can try using Tight VNC better(In the past we used Tight VNC to access the old Windows 8).

xrdp running under lununtu seems to create a separate session versus ununtu. I don't know why at the moment. I would not use tightvnc over the internet without using a VPN or via ssh.

Over the internet the PC wasn't reachable(over our own VPN), over our network it works.

Is there somewhere a good manual to do SSH

Perhaps see The Wikibook on OpenSSH, and in particular the chapter on remote access. There are discussion pages there for improvement requests. For questions about usage keep asking here. There are good reference manuals, but they are not tutorials or guides, see in particular "man ssh_config", "man ssh", and "man ssh-add".

There's a lot to SSH, but at its core it is just like the local shell except that you connect to the remote system first. Therefore any basic shell tutorial applicable to your distro of choice (any of the *buntus, and probably most APT-based distros too) would also be relevant.

Not being reachable over your own VPN would be something to ask your IT people. You would have the same problem with ssh over the VPN as well. I would expect your IT people might not allow a direct connection via ssh since you already have a VPN.

If what you are setting out to do is to build a kiosk, there are off-the-shelf commercial software systems available which do that (for you). Of course, most of them are based on Linux. Simply toss a few bucks in the direction of other programmers who have already done the dirty work for you . . . they deserve it.

"Internal connectivity issues" are always something to be directed to "the internal IT department." Most "enlightened" companies use VPN exclusively, and they restrict "everything 'ssh'" to VPN users. In this way, their 'sshd' is never directly exposed to 'the howling hoards outside.'

If it is on a lan only then you could add in a hosts file name. This assumes you have a dhcp reserved or static IP. Otherwise you have to fool with ms names.