Wait, but you did change the files in the /boot directory?

This is so weird. Did you change any of these files you mentioned earler?

/kernel
huge.s
bzImage
config
system.map.gz

OK, so that does not make much sense. There is nothing at that point that has to do with the new kernels. It should have worked exactly as the original iso.

Can you try the original iso, without the updated kernels? Does it go past that point?

What if you don't try the keyboard and get to the next dialog?

At what point exactly does it freeze? You say "Just after trying the language". Is that right at the grub menu when you select the language to boot the installer? Or is it when you're trying out the keyboard, after the installer starts?

No, not the kernels directory. The kernel and core directories that are inside the salix directory. That is where you will find the packages. Delete them from the iso and then put the packages from slint in their place. You don't have to use the slint iso. Just download the packages from the slint ...

Ah, I should have probably added more details on what "Don't forget to update your lilo/grub" meant. That's why you're getting a kernel panic.

To answer your last question, yes! This is not widely known, but you can replace packages on the iso! You can open the iso with isomaster, delete all the ...

Just remove the ones you have and install the 4 packages from the slint repo. Don't forget to update your lilo/grub.

No, it isn't the temperatures. But do check your RAM with memtest. Freezes like these most of the times are hardware issues, unfortunately.

You could also try a newer kernel. You could try the kernel packages from slint: http://slackware.uk/slint/x86_64/slint-15.0/slint/

A few minutes is enough time for the system to cool down. Add a temperature monitor in your taskbar, so you know exactly the temperature when it hangs.