Windows 7 Backup ZIP Extractor

A simple, maintainable Python 3.x script to extract and reconstruct files from Windows 7 backup ZIP sets named Backup files N.zip. It preserves internal paths, concatenates split parts in correct order, and writes a text summary log.

Requirements

• Python 3.x on Windows.

Usage

Run from this folder or provide full paths.

• From a directory of backup ZIPs: python winbak_extract.py --dir "C:\\Backups"

• From explicit ZIP paths: python winbak_extract.py --files "C:\\Backups\\Backup files 1.zip" "C:\\Backups\\Backup files 2.zip"

• From a parent folder containing multiple "Backup Files" folders: python winbak_extract.py --set "C:\\BackupSets"

• Optional filename encoding (used when ZIP entries aren't UTF-8): python winbak_extract.py --encoding cp932 --dir "C:\\Backups"

  • If UTF-8 flag is set in a ZIP entry, UTF-8 is used regardless.
  • If UTF-8 flag is not set and --encoding is provided, that codec is used. Refer to Standard Encodings on Python documentation for available codecs.
  • If UTF-8 flag is not set and --encoding is omitted, CP437 is used per ZIP spec.

Examples

• Basic directory processing: python winbak_extract.py --dir "D:\\Win7Backup"

• Process a Backup Set folder (immediate children only): python winbak_extract.py --set "D:\\Win7BackupSet"

• Explicit files: python winbak_extract.py --files "D:\\Win7Backup\\Backup files 1.zip" "D:\\Win7Backup\\Backup files 2.zip"

Behavior

• Filters only files named Backup files N.zip (case-insensitive), natural-sorting by N.
• Extracts each ZIP entry to a dedicated temp directory: <dest>\\.winbak_tmp\\<internal_path>\\<name>.part_0001....
• Groups occurrences of the same relative path (case-insensitive on Windows) and treats them as parts.
• Merges parts in natural ZIP order using copy /b with a Python fallback if needed.
• Overwrite policy: triggers failure and skips if the final output already exists.
• Dedupe behavior: identical duplicates are always treated as parts and concatenated.
• Deletes staged part files after a successful merge.
• Optimized single-part handling: if only one part exists, it is moved directly to the final destination (size-verified) instead of re-copying.
• Writes timestamped summary logs winbak_extract_YYYYMMDDTHHmmSS+HHMM.txt (merged files, part counts, skips, errors) to each processed folder.
• Serial processing; streams I/O; avoids loading entire files into memory.

Path Length

• Supports extended-length Windows paths using the \\?\\ prefix for open/replace/unlink operations.
• If very long paths still fail, ensure Windows long paths are enabled (may require registry change and policy updates).

Exit Codes

• 0: Completed without errors.
• 1: One or more errors occurred (see summary log).

Notes

• Aligns with the manual guidance for combining split parts using copy /b, but avoids wildcard patterns and enforces explicit order.
• Final outputs are written under <dest>\\<internal_path>\\<name>; temp artifacts live under <dest>\\.winbak_tmp.
• On completion (even if failures occurred), empty directories under .winbak_tmp are pruned bottom-up; the root is removed if the tree is empty.