Microsoft Windows 9x Invalid Driver Type DoS Vulnerability
If a Microsoft Windows 9x client connects to a File and Print share and the server returns an invalid driver type, the client will crash and a reboot of the system is requied in order to regain normal functionality.
The following driver types are the only valid driver types that Windows 9x can handle:
2) Drive Letter:
Any driver type returned to the client other than these will result in a denial of service.