I have for a few years installed and tested several mainstream distros with the aim to replace Windows. Then I started to test those distros that runs well in a USB stock with persistance. After that I narrowed down to a distro that can run across different hardware configurations so that I can also use it as a recovery tool. So I now use Puppy Precise 5.7.1 LTS.

I wonder if there are others which are as strong as Puppy with the following strengths:
- Runs on USB stick with persistance
- Runs on old and new hardware
- Compatible with ATI and Nvidia
- Full GUI interface and do not need command line
- Do not need cutting edge releases.
- Stability and compatibility are most important

Any ideas will be appreciated.

I've noticed that the recent OpenSUSE live images, when flashed to a USB, on the first boot create a persistent partition in the remainder of the space on the drive and then map the root filesystem over to it. I haven't played with it too extensively to see how far the persistence extends (can you install packages and have them carry through, system updates, etc.), but it looks promising.

Everything almost can run on a usb but it would be better to be a proper install instead of a live to usb install with persistence. Get a good fast usb to start with.

You kind of have to have command line for most distro's just for some background things.

I usually let it or force it to run vesa mode and not fool with video issues.

Exactly how old do you mean? Puppy can run on some pretty basic stuff that would kill any chance of Gnome or KDE.

Check out - http://antix.mepis.com/index.php?title=Main_Page

Porteus Linux
www.porteus.org

should fulfill your requirements.