This error is occuring because the InterBase install is installing file setupapi.dll and stomping on an already installed version of setupapi.dll. Some users have reported that if you simply ignore the error and continue InterBase is successfully installed. Other users have reported this is not the case, especially those with service pack 2 installed.
One solution is to copy the Windows install portion from the InterBase CD to a location on your hard drive, rename the setupapi.dll that comes with InterBase to some other name, then copy setupapi.dll from driveletter:WINNTsystem32 to the InterBase install you copied from your CD and try the install again from your hard drive. With this method the correct setupapi.dll will be installed.
Another solution is to revert to Service pack 1, install InterBase 5.x, then reinstall service pack 2, or install InterBase 6 instead. (InterBase 5.x is not certified with Windows 2000.)
For more on DLL compatibility problems see the article "The End of DLL Hell" on MSDN Online.
Last Modified: 19-OCT-01