title_body: How can we validate an ePub3 file in Windows 8 system We have validate an ePub files in the epubcheck-3.0.1 version in windows 8.1 system, and we received below error message in the epub files. could you please help for us?
  
  ERROR: 9088098774672.epub: Mimetype entry missing or not the first in archive
  Validating against EPUB version 3.0
  
  Check finished with warnings or errors
upvoted_answer: This error is not related to Windows itself. This means that ePub file is bad compressed. Decompress this file and compress it via this tool ePubPack