Yesterday my Dell Inspiron 15 was running Kali fine. I saw there were a lot of updates available, so I installed them.

Problem #1: when I boot Kali I get an alert saying "Low Disk Space on "boot". The volume "boot" has only 473 kB of disk space remaining".

DF command
Filesystem 1k-blocks Used Available Use% Mounted On
/dev/sda1 240972 228069 462 100% /boot

ls /boot
config-4.13.0-kali1-amd64
config-4.6.0-kali1-amd64
config-4.9.0-kali3-amd64
config-4.9.0-kali4-amd64
grub
initrd.img... (x7)
lost+found
System.map-4.13...
System.map-4.6...
System.map-4.9...
System.map-4.9...
vmlinuz-4.13...
vmlinuz-4.6...
vmlinuz-4.9...
vmlinuz-4.9...

Problem #2: looks like Kali has forgotten that my laptop has a wireless adapter. It's not showing when I open the menu in the top-right corner.

I suppose the lack of wireless functionality is the larger problem. To free up space on boot, could I just delete everything that contains "4.6" and "4.9", and leave everything with "4.13"? Thanks.

Uname -r: 4.13.0-kali1-amd64