Thanks for all that input, Barracuda, but you overestimate my Linuxarian skills. I do not touch level 4 and level 5 ugrades and changes because they root too deep into the system and I have no clue how to repair something when it breaks. Stability and safety first, Linux is no playground for me. I only want it to run stable and safe, and provide me with a protected environment from which to browse, email, write texts, edit photography, and rarely do some shopping or banking stuff. This has absolute priority. Kernels I do not manually touch as long as a Mint version upgrade does not do it by itself.
As I described, the ISO came from several different sources, and all these sources were tried by severla different systems, and people, so we had for exmaple 18.0 from source A done by person A, then person B on his system, then person C on his, they tried them amongst themselves later and swapped disks, and I tried them as well, on my device.
Think of it. The result really is a punch in Mint 18's face. In most cases it did not work for anyone of us. My problems, stealign my breah for ten days, result from this inherent unreliability. I tried several ways to install, several versions, DVD as well as stick. When you have five, six different ISO tried and none works, you do no longer think that the problem might be hidden there, and go searching elsewhere.
BTW, the cooking party has been cancelled, I got a call. Maybe this guy twice as old as they are started to beocme eerie for them.
When I offered that as a way to say thanks, I was surprised anyway that they accepted the idea, it was not really meant too serious by me. There is semester break holidays over here, and it is Friday night, think young guys have better things to do then. Its okay. Hm, a relief even, maybe.
But it was a curious event, a curious way to meet, and they really were
extreemely helpful. I keep a pleasant memory.