simple download of offline installers in firefox doesn't work for you? :-o I can't recall having problems, but I never downloaded any really big one, the largest was probably about 5-6GB, which takes just some minutes (maybe hour, etc.. i.e. less than I notice, when I'm doing other things on the computer meanwhile).

I once tried uGet for Linux, it's open source and works really well, also has pause and resume support. https://ugetdm.com/

First time I have had severe problems with a Linux kernel. My computer, Mint 18.3 and kernel 4.4.0-137 just do not go well together. Had problems starting the computer and resuming from sleep so I tried reverting to an older kernel and all is well again :-)

Your kernel is ancient. Just use the newest kernel.

The 4.4 series is what is standard in LM 18.3 and it keeps getting small updates (security I presume). I had problems with the latest when I tried it back when I upgraded from Mint 17.3 but the latest might work nicer with my antique hardware now, maybe. I might try on Friday. Much newer kernel on my desktop.

It's causing problems on a lot of recent hardware. I'm surprised Mint are using such old kernel.

Linux Mint 18.3 shipped with 4.10 by default; you'd only be using an older kernel if you had upgraded from a prior release and hadn't installed a newer kernel. Mint 19 ships with kernel 4.15

Oh, I might have done that... cannot remember. Now you good people have convinced me to upgrade tonight already.

Thanks to both of you!

This reminds me of when I installed Mint 18.1 on my Ryzen system, everything worked except the network kept disconnecting every few minutes. A kernel update resolved the issue right away. I'm happily sitting on Kernel 4.15.18 now and the system is super stable. I'm still rocking Mint 18.1 as it works fine despite being a little dated, I'll upgrade it to Debian 10 when it lands. :-)

I'm constantly trying newer kernels before they even get into distro (I'm on KDE neon distro, based on Ubuntu, so these: https://wiki.ubuntu.com/Kernel/MainlineBuilds - works for me), on MSI gaming notebook.

I had very good period with 4.17 kernels, can't recall any problem, now I tried 4.18.11 and got one complete freeze of PC, so I went for 4.18.12 ... (but the freeze may be unrelated to kernel, anyway, it happened right around that time I tried it, and there was .12 available, so I have no sentiment to move forward and test the newer one).

You can install the latest one from several series and then pick in the boot menu which one you want to test, something ought to work for your HW, the kernels are reasonably stable overall (but the PC HW market is insanely broad and complicated, so it's still possible to run into problematic combinations).

Hooray! The latest kernel offered in the official list when I look in the updater rendered my laptop a brick :-(
No matter how many times I restart normally, I am never greeted by anything else than the whooshing sound of the cooling fan. Good thing I made backups before this. Anything I can do when I never see a booter?

(Now to make backups on Windows 10 computer as well before installing the autumn upgrade.)

That's quite unusual. Under Fedora if I choose to update the kernel the new version installs alongside the old one and I am able to pick one via GRUB menu, so even if the new kernel is dysfunctional, there is always an opportunity to fall back. If there is no GRUB menu at all, then something truly bad happened. :(
Hmm… F2? F8? Del?
Try to get to the BIOS and pick the boot drive from that. See what happens. If the BIOS is still intact then maybe USB DVD-drive or bootable flash-drive can get you to the Live Distro. Then there are plenty of ways (from chroot'ing to the broken OS and downgrading the kernel to the simple reinstall).

Oh thanks for suggestions. Will try after finished backing up these photos.

I always have a USB stick with some OS on it but cannot seem to find it now and due to need for massive backups lately all other sticks are in use but there should be an empty dvd disc somewhere here. It has saved me before :-)

My problem also might be that the laptop belongs among the waste.

That's weird. Are you using UEFI? Sometimes grubx64.efi gets messed up, or rather your EFI variables get messed up, because firmware is flaky, its storage memory fills up and etc.

One recommended step is to check what's in /sys/firmware/efi/efivars/*

If you see a bunch of stuff like dump-*, delete it.

I.e.:

rm -v /sys/firmware/efi/efivars/dump-*

that should free some of your firmware memory.

Then, if your actual grub efi wasn't corrupted, do this copy (create the target directory if it's missing):

cp /boot/EFI/debian/grubx64.efi /boot/EFI/boot/bootx64.efi

That will create default efi image that all firmware should boot from. Reboot and if GRUB comes up, boot your kernel and after that, check your efi variables with:

efibootmgr

If debian / mint is missing there, do the following (you can call it like Mint would, I'm not sure, Debian uses "debian", but it's not critical):

efibootmgr -c -l "\\EFI\\debian\\grubx64.efi" -L "debian"

That should restore your EFI variable entry.

If you have such flaky efi firmware, I recommend doing this step after each apt-get dist-upgrade. I wrote a script for that very case for some of the older hardware I encounter. It checks if grubx64.efi differs from bootx64.efi and makes a copy if so, and then checks if efi variable is there and creates it if it's missing.

NOT using UEFI since it was not invented when my laptop was made back in 2007. It might be that kernel expected UEFI and either has no support for BIOS or needed some of those whatever-they-are-called looks like this: -option B