Why is my network messed up after update to windows 11 24H2

Thank you for your comment. If you figure it out, please post it, because other people are having the same problem. Still I am sticking with Windows 11 for many reasons. Nonetheless, after having so many issues with networking (as are thousands of other users), I was tempted to experiment with other OSs. I really like Synology NAS, but now they are requiring that users utilize "approved" storage device brands, which I think is abusive. My favorite NAS now is TrueNas because of the ease of use, but Open Media Vault is simpler and has interesting apps (which Truenas Scale no longer has). I have used Windows 11 24H2 on 13 year old machines without a hitch, but none accepts connections from other computers without a user password. Even when we choose to share with "everyone" on the network sharing settings. I heard it is a security issue, and I will accept it for lack of a plausible explanation. Up to Win11 23H2, everything ran as smooth as can be.

Kubuntu (KDE Ubuntu) runs all the applications Windows does in their Linux versions and is compatible with all Windows hardware I have used so far, even wireless internet dongles and cards. Bluetooth also works like a charm. When using it, I cannot tell the difference, except that it does not require new hardware. One of my Kubuntus is running on an AMD FX8, 16 GB RAM and a stupid 2GB NVidia video card I plucked from an old computer I picked up from the garbage, and an the other runs on an i5 3rd gen Dell 990 SFF. The HDMI works beautifully on both. Networking works very well on SMB protocol, but it is slow.

I am wondering why the SMB protocol is deinstalled with every update at your machines.
I migrated from Windows 10 to 11, had 24H2 installed afterwarts. No straight upgrade of the network, as I hoped. But after putting the protocols correct, I do not have to correct them again with every update of the 24H2.
In my network runs a Synology NAS, some Windows 11 machines and some Windows 10 and 1 Ubuntu. The Windows 10's and the Ubuntu are older machines not compatible with Win11 at all.
I made some shares on the Windows 10 machines as for some reason I need to copy files to them. No problem with the shares on the Synology nor the Win10 machines.
So, I'm wondering what triggers Win11 to remove every time the SMB protocols on some machines and not on another.

Though I agree with the monopoly part, I need to say there is nothing out there with the same level of compatibility with current software. Apple is guilty of the same sin you denounced. However, the current situation has opened my mind to other avenues: I created two NAS file servers, one with Truenas scale and another with OpenMediaVault. I noticed that both work flawlessly with SMB protocol - even better than Sinology NAS. I am testing both and will stick with one. As for inter-connectivity between the network, I caved in and created passwords for every computer on the home network and enabled password required when accessing them option. I also created a Windows 11 file server which is super fast. The caviats with NAS is that if the system breaks, you cannot easily recover the files from their hard-drives. An easier solution is to use 2 storage HDD on each NAS. Another way is to make one replicate itself on another NAS. Neither is a "little-hardware" solution, but all will do the trick. I still don't understand why every update to Windows 11 24H2 uninstalls the SMB protocol, making you go back to control panel and re-install them. What is the purpose in doing it? We'll find out some day with Windows 12. I also created a Kubuntu machine for testing. It works like a charm, but slow.

I will tell you all why your network is messed up, because Microsoft designed Windows 11 that way. They don't want you using computers that worked for decades, like the two I have to function with Windows 11, With the Network so screwed up, they think they can force you to replace all of your devices for newer ones. They say they are updating software, ie Windows 10 to Windows 11, but all they really do, is move stuff around, change the name slightly, locate it in a different catagory to make it difficult to find, and then they put bugs in it that won't allow you to use your system the way you want to, unless you go buy all new systems, which by the time you get them up and working, will be obsolete and have to be replaced over an over.

I have a Dell 4600 running Windows XP and a computer running Windows Vista, both function as they have always done, only now without support, but neither has ever been hacked, I use them for storage mostly. I have tow docking stations with over 30 T of Storage. I capture and edit movies on the Dell and store them on the docking statiions. I have an HP with windows 10 that connects easily on my Home network to the two OLD computers but this one a newer HP laptop, that did connect until I was force to upgrade to windows 11.

Microsoft has a MONOPOLY, and to keep that MONOPOLY at the top of the heap, they keep putting out new programming, that really isn't new, but with bugs in it to force you to update on a regular basis and spent several hundred dollars for devices and systems that can on connect with similar devices and systems. THEFT by DESIGN.

Same problem. System restore helped aon one computer but on another it wouldn't work correctly. A system image re-install did fix the other. However, these problems are consistent for many people after the Win update. The update makes many changes to settings that control the network. Ask Microsoft why they put out an update that changes preferences you already had functioning fine. Good luck.