A Windows reinstall often removes the software needed to open certain file types. For Nikon .NEF files, Windows may need the Nikon NEF codec or Nikon software to preview/open them, and Word documents will require Microsoft Office or another compatible application.

So first, reinstall the programs you used before the crash:

• your Office suite for .doc files
• Nikon’s NEF codec or Nikon image software for .NEF files

However, because you mentioned other file types also won’t open, this may not be only a missing-codec problem. If files that existed on the computer before the crash are failing while other newer files open normally, that points to possible file corruption or a failing drive.

In short:

1. Reinstall the required applications/codecs.
2. Test several files, especially ones from different dates or backups.
3. If multiple file types still won’t open, suspect drive damage or corrupted files and try to recover/restore from backup.

For the future, keep regular backups, especially on a laptop, since crashes and drive failures can damage many file types at once.