Windows Vista and Windows 7 users should enable Windows XP compatibly mode. Windows XP compatibly mode should also be applied to all virtual hardware devices. To further minimize incompatibly problems, it's recommended to run both the emulator and any virtual devices as system administrator.

READ/WRITE access is required for these files:
C:\emu8086.io
C:\emu8086.hw

(these files are used to communicate with virtual devices and for emulating hardware interrupts)