During PC startup, which of the following is a common cause of a “fixed disk error” reported by the BIOS or POST diagnostics?

Introduction / Context:
Older BIOS setups require correct drive parameters (type, cylinders, heads, sectors, LBA/CHS mode) to recognize hard disks. Misconfiguration can trigger a “fixed disk error” during the power-on self-test (POST), halting the boot process or making the disk inaccessible.

Given Data / Assumptions:

• We are diagnosing a POST-level fixed disk error.
• Legacy systems rely on CMOS/BIOS configuration for drive geometry.
• No additional symptoms are specified.

Concept / Approach:

If the CMOS contains wrong parameters (incorrect drive type, disabled controller/port, wrong LBA setting), the BIOS fails to identify or properly access the hard disk, reporting a fixed disk error. Correcting CMOS values or auto-detecting the drive typically resolves it. While failing RAM can cause various issues, a specific “fixed disk” message usually points to disk/controller configuration or hardware faults.

Step-by-Step Solution:

Verification / Alternative check:

Service manuals for legacy PCs list incorrect CMOS geometry or disabled ports as a primary cause of fixed-disk POST errors. Successful auto-detection typically validates this diagnosis quickly.

Why Other Options Are Wrong:

• Bad RAM: can cause random crashes, but not a targeted fixed-disk geometry error.
• Slow processor: has no bearing on disk identification at POST.
• No-CD installed: optical drive presence is unrelated to a fixed disk error.
• None of the above: incorrect because wrong CMOS settings are a well-known cause.

Common Pitfalls:

• Overlooking disabled storage controllers after a CMOS reset or battery failure.
• Mismatching cable positions (master/slave on PATA) or SATA mode changes (AHCI/IDE) without drivers.

Final Answer:

Incorrect CMOS settings.