i have really trouble make neo lemmix working my computer. Probabably 97 windows in too old.
That 97 can't be right. There's Windows 95 and then Windows 98. But I hope you're really just on Windows 7 which came out much later than 1997.
If you are really using Windows 95 or 98, at least please don't do your web browsing on that same old computer, it is completely insecure at this point, and you don't even have the option to use a non-Microsoft web browser since I'm pretty sure all the popular ones have dropped support (or in some cases, never had support) for Windows 95/98 a long time ago (some even dropped XP support a few years ago).
It's also interesting that the plain vanilla Lemmix players still worked on your computer but not NeoLemmix. Of course there had been many changes from one to the other, but it isn't obvious that somwhere along the way things no longer work past some older version of Windows. I'm more suspecting maybe something else is going on and there are some ways past the errors you are hitting to get NeoLemmix working on your computer.