1.) Are you using WordPad to open this .DOC file? Changes between versions of WordPad in Windows 8 and Windows 10 might prevent the file being opened.
2.) If you use Word 2007 or later to open your .DOC file, did you alter options in the 'Trust settings' from Office? Review these yourself or if you don't know, let someone with knowledge/experience do it for you. Then, if possible, save your .DOC file as a .DOCX file to make it more future-proof. This has to do how the document is structured. Say, for example, you have made a document with Word version XP and saved it as a .DOC file. If you want to open this file with Word version 2010 or later, Microsoft deems the file and how it is structured to be unsafe and therefore won't open it by default. You must enable this by adjusting the 'Trust' settings.
3.) Download a (portable) version of LibreOffice (open source and free) to open your .DOC file. Then, if possible, save your .DOC file as a .DOCX (or .ODF) file to make it more future-proof.