Operating system upgrades: Which of the following is LEAST likely to interfere with upgrading to a newer DOS version?

Introduction / Context:
Upgrading legacy DOS systems can be impacted by hardware compatibility, BIOS behavior, and storage configurations. Correctly identifying non-issues saves time and reduces risk during migration steps such as boot disk preparation and SYS/FORMAT operations.

Given Data / Assumptions:

• Standard PC with ROM BIOS and video controller.
• Some systems used drive compression utilities that affect boot and file access.
• Backup files are simply data stored elsewhere on the disk or external media.

Concept / Approach:
ROM BIOS and certain video adapters may require specific DOS versions or drivers. Compressed drives (e.g., DoubleSpace/DriveSpace or third-party tools) can complicate boot loaders and file access during upgrades. By contrast, existing backup files are benign and do not interfere with the upgrade—indeed, they are recommended before any OS change.

Step-by-Step Solution:

Verification / Alternative check:
Vendor upgrade notes often warn about drive compression and video/BIOS compatibility but never about the mere presence of backups.

Why Other Options Are Wrong:
ROM BIOS or video may require patches; compressed drives can break boot sequences if mishandled.

Common Pitfalls:
Forgetting to uncompress or provide the right drivers before upgrading; misidentifying backups as “unused files.”

Final Answer:
Existing backup files