Unknown internal operating system error

Hello,

   I have done an application that, on Windows 98, it runs OK, but, on Windows NT, it sends the following messages:

Unknown internal operating system error.
Bad file number.
File: C:\Fontes\TSC\1.40\Dados\Receita.PX

   I have developed my application on C++Builder 5.0.

   Do you know what I can do ?

Thanks,

                     Vilson