>>>>>I forgot to say it's fpw2.6a
>>>>>And your recommendations didn't help.
>>>>>
>>>>>I think it has something to do with NTVDM and/or wowexec, but I'm not sure. The DELL-computer is, according to DELL, the same computer with a faster CPU as a computer that works with a 2.0 GHz CPU.
>>>>>And it works with win2000.
>>>>
>>>>Is the fast CPU patch applied? http://support.microsoft.com/default.aspx?scid=KB;en-us;q240982
>>>
>>>yes, and fox runs under WIN 2000 but not WINNT
>>
>>Is it one particular machine that doesn't work, or more than one? If it's just one, try simplifying - disable antivirus software, disable unnecessary services, etc.
>
>I thouhgt that it was that at first, the machine I got was "Ghosted". So I did a clean install of WINNT.
>It's strange that fox runs under WIN 2000 though. And my customer even tried WIN XP and there was no problem.

Hmm, can't think of much else to try. I'm assuming you're doing all of your testing while logged in as a local administrator, and that all NT Service Packs are applied?