Ubuntu 26.04 LTS ‚Resolute Raccoon‘ – release notes – requires a 2 GHz dual core processor or better a minimum of 6 GB RAM and 25 GB of free hard drive space
If you are currently using an older Ubuntu LTS or interim release such as Ubuntu 22.04 LTS or 25.04 you must first upgrade to either Ubuntu 24.04 LTS or 25.10 before you can proceed to 26.04 LTS