DOS utilities: At a DOS prompt, which command displays a summary of memory usage and the amount of memory available?

Introduction / Context:
Legacy DOS tools are still referenced in certification exams and basic troubleshooting. The MEM command provides a quick overview of conventional, upper, and extended memory usage, including drivers and TSRs, which is invaluable when diagnosing low-memory issues.

Given Data / Assumptions:

• MS-DOS or DOS-compatible command line.
• Goal: see how much memory is free and where it is consumed.
• Common related tools include CHKDSK and MEMMAKER.

Concept / Approach:

MEM outputs totals and breakdowns of free and used memory. Switches like /C list drivers and TSRs with memory blocks, while /P paginates output. CHKDSK primarily checks disk and filesystem structures; MEMMAKER optimizes memory usage but does not directly display a live summary like MEM.

Step-by-Step Solution:

Verification / Alternative check:

Compare MEM output before and after removing TSRs to confirm reclaimed memory.

Why Other Options Are Wrong:

• EMM: not a DOS command; refers to Expanded Memory Manager conceptually.
• CHKDSK: reports drive and file structure statistics, not memory usage summary.
• MEMMAKER: optimization wizard, not the real-time summary tool.
• None of the above: incorrect because MEM is correct.

Common Pitfalls:

Confusing conventional memory limitations with XMS/EMS; forgetting that high memory loading depends on HIMEM/EMM386 drivers and device configurations.

Final Answer:

MEM