How to easilly downgrade kernel to 4.4?
I would like to downgrade kernel to make my WIFI USB ADAPTER work.
What is the easiest way to downgrade kernel?
Does Fedora have any software to do that except in Terminal?
There is no easy way for that. What Fedora release are you running? 4.4 was used a long time ago, so it probably was never build for your more recent Fedora release.
You can try to find a 4.4 release here or here and try to install it. However, be aware that it is probably not for your Fedora release and not an (updated) recent 4.4 kernel.
I would suggest you try fixing the Wifi problem differently. Has the wifi question been asked here somewhere?
I would expect that
systemd
will depend on the current kernel version, as a lot of the features needed were not provided by kernel 4.4. If you must, you should probably find some older Centos system and use that.Personally I would consider buying a supported USB wifi adapter.