After adding a second PnP NIC (IRQ 5) to a Windows 2000 print server, printing to a non-PnP LPT2 adapter stops working. How should you ensure the legacy LPT2 IRQ remains available?

Introduction / Context:
Legacy parallel ports typically use hardware interrupts: LPT1 often uses IRQ 7 and LPT2 often uses IRQ 5. Non-PnP adapters cannot negotiate for interrupts; they simply expect the traditional IRQ. When a new Plug-and-Play NIC consumes the same IRQ as a legacy device, the legacy device appears to ‘‘fail’’ because its interrupts are stolen by the PnP device.

Given Data / Assumptions:

• Second NIC uses IRQ 5.
• Non-PnP LPT2 historically uses IRQ 5.
• Printing stops only after installing the second NIC.

Concept / Approach:
Reserve the conflicting IRQ in BIOS/CMOS for non-PnP/ISA devices so the PnP resource allocator avoids assigning IRQ 5 to the NIC. This preserves IRQ 5 for LPT2. Device Manager changes typically do not apply to non-PnP hardware, and moving LPT2 to IRQ 7 would conflict with LPT1’s conventional assignment.

Step-by-Step Solution:

Verification / Alternative check:
Use Device Manager and hardware diagnostics to confirm the NIC no longer uses IRQ 5 and that the parallel port driver registers its expected IRQ.

Why Other Options Are Wrong:

• Changing LPT1/LPT2 IRQs in Device Manager rarely fixes non-PnP conflicts and can introduce new conflicts.
• Reserving IRQ 7 addresses LPT1, not LPT2.
• ‘‘None of above’’ is incorrect because reserving IRQ 5 is the targeted fix.

Common Pitfalls:
Overlooking BIOS ‘‘PnP OS’’ settings and IRQ reservations; always protect legacy resources before adding PnP adapters.

Final Answer:
Edit the server BIOS/CMOS to reserve IRQ 5 for non-PnP devices