Be sure that "PNP capable OS" is disabled in your Bios.
If it still doesn't work, try a different PCI-slot, that worked for me !
The following files are found inside the driver download file.
|WIN95/README.TXT||2.4 KB||23 Mar 1999|
|WIN95/DM9PCI.SYS||30.5 KB||10 May 1999|
|WIN95/DM9PCI.DOS||46.8 KB||18 Mar 1999|
|WIN95/NETDM.INF||6.5 KB||28 Apr 1999|
|WIN98/README.TXT||2.5 KB||23 Mar 1999|
|WIN98/NET5DM.INF||9.2 KB||30 Apr 1999|
|WIN98/DM9PCI5.SYS||37.8 KB||10 May 1999|
|WIN98/DM9PCI.DOS||46.8 KB||18 Mar 1999|