Hello,
I've just bought a new HP laptop and I installed Debian Strech (9.5) on it. I has an ryzen 5 2500u CPU and it seems to run fine for now with the exception that I'm missing the wireless network card. I've looked at the used kernel and it seems to be 4.9 (quite old). So I've read about the strech-backports repository which would contain a newer kernel (which maybe has the drivers I need).
I've added the repository in the sources.list but apt-get update doesn't work.
I get the following error messages:
Error:9 https://deb.debian.org/debian strech-backports/main amd64 Packages
404 Not Found
W: The repository 'https://deb.debian.org/debian strech-backports Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Eșec la aducerea lui https://deb.debian.org/debian/dists/...amd64/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.


Below is the content from my sources.list:
cat /etc/apt/sources.list


# deb cdrom:[Debian GNU/Linux 9.5.0 _Stretch_ - Official amd64 NETINST 20180714-10:25]/ stretch main

#deb cdrom:[Debian GNU/Linux 9.5.0 _Stretch_ - Official amd64 NETINST 20180714-10:25]/ stretch main

#deb http://ftp.ro.debian.org/debian/dists/ strech main contrib non-free
#deb-src http://ftp.ro.debian.org/debian/dists/ strech main contrib non-free

deb http://deb.debian.org/debian/ stretch main contrib non-free
deb-src http://deb.debian.org/debian/ stretch main contrib non-free

deb http://security.debian.org/debian-security stretch/updates main
deb-src http://security.debian.org/debian-security stretch/updates main

# stretch-updates, previously known as 'volatile'
deb http://deb.debian.org/debian/ stretch-updates main
deb-src http://deb.debian.org/debian/ stretch-updates main

deb https://deb.debian.org/debian strech-backports main contrib non-free

#deb http://ftp.ro.debian.org/debian/dists/ strech-backports main contrib non-free
#deb-src http://ftp.ro.debian.org/debian/dists/ strech-backports main contrib non-free

Hello there.

You've got a little typo, change strech to stretch then do an:

and all is good.

Ref: https://backports.debian.org/Instructions/

Thanks a lot. That was the problem. I was too tired to notice and I've been searching for answers for hours ).

You are welcome. Please mark it as solved from your original post.