Reformatting checks in MS-DOS Which FORMAT option forces DOS to recheck all disk clusters during a reformat, including those previously marked bad?

Introduction / Context:
Formatting media in DOS can either trust existing bad-cluster maps or retest all clusters. When verifying media health, technicians may force a full recheck to ensure no latent defects are missed.

Given Data / Assumptions:

• We are using the DOS FORMAT utility.
• Goal: retest clusters, including those previously marked bad.
• We compare common switches: /B, /S, /8, /C.

Concept / Approach:

FORMAT /C directs DOS to examine clusters that were previously marked bad and recheck the surface, updating the bad-cluster list as needed. Other switches serve different purposes (system transfer, boot area, legacy geometry).

Step-by-Step Solution:

Verification / Alternative check:

Compare a run with and without /C on media with known bad clusters; /C triggers a recheck and may clear falsely marked clusters or confirm genuine defects.

Why Other Options Are Wrong:

a: /B reserves space for system files or boot tracks; not a cluster retest directive.

b: /S copies system files to make the disk bootable; unrelated to cluster checking.

c: /8 formats for 8 sectors per track (legacy); not a testing option.

e: Not applicable because /C is correct.

Common Pitfalls:

Confusing /U (unconditional format) with surface retesting; /U affects UNFORMAT recovery, not the retest behavior itself.

Final Answer:

FORMAT /C