Don't worry about M.2 slots or USB 3.0, SATA III. All these can be added with a PCIe expansion card. For instance, I use a PCIe USB 3.0 card in my Intel socket 1155 motherboard and I am fine. I could also use a PCIe M.2 card, but I don't have any free PCIe 1x slot. I don't care, my SATA SSD is fast enough for my needs. For those wondering, back when I bought my Intel socket 1155 motherboard I had 3-4 legacy PCI (not PCIe) cards in my old computer I wanted to keep using. This model, Asus P8H61, was the only one with three legacy PCI slots, but this had no SATA III or USB 3.0. I had to either choose new technology and one legacy PCI slot, or three legacy PCI slots so I chose the latter. I can add USB 3.0 or SATA III with a respective PCIe card, so I didn't care. Needless to say there are Windows 7 drivers for this old hardware, so I could run Windows 7 64-bit fine until I upgraded to Windows 8, then 8.1 and later 10. Now I am running Windows 11 without any issues. All I had to do was bypass hardware compatibility check to install or upgrade from one version of Windows 11 to the next.
PS: I too don't like the plain flat icons of Windows 10/11, so I used Customizer God to extract all system icons from Windows 7 and 8.1 and use them in Windows 10/11. I have replaced all those ugly system icons with the respective icons from Windows 7 or 8.1 (for those that didn't have a Windows 7 equivalent). I have also installed 8gadgetpack to use my old Windows 7 gadgets, Open Shell (formerly known as Classic Shell) to have the Windows 7 start button and start menu and Winaero utilities to get the old versions of Calculator, Microsoft Paint, Notepad and others. Now that I have completely transformed Windows 11, they are not that bad. I have even installed the good old "Windows Lite" theme (the one with the familiar red close icon on top right of each application).
PS2: I had downloaded the Beta version of Windows 10 and installed it on a virtual machine to have a look at the new features before I upgrade from 8.1 I was shocked to see VERY UGLY icons, almost seem like drawn by kindergarten children! I almost swear to never upgrade to Windows 10! Everyone was demanding to change these ridiculous icons, so the official release of Windows 10 had nicer redesigned icons, but they are still very flat compared to the 3D icons icons of Windows 7 and 8.1 I wouldn't mind using the original system icons of Windows 10/11 but they are too flat for my taste. The default Windows 11 icons are redesigned and a little nicer that those of 10, but still I prefer the Windows 7/8.1 icons and hence the customization. You can read all details in the respective threads in Personalization section of
Tenforums and
Elevenforum.
Windows 10 Beta vs 21H2 Release Icons! (youtube.com)