Windows 11 requirements
One check you can make yourself, is how much memory you have. Win 10 requires a minimum of 2GB of memory, but Win 11 will require twice this. To check how much memory you have, do the following:
Press the Windows key and I. Windows Settings screen will appear. Now click the system icon top left. On the left, scroll to 'About' at the bottom. On the right, under the heading 'Device specifications', you will see 'Installed RAM'(memory).
Other checks are too technical for this loop. My PC has failed the first two checks!