Windows 10 is a great update with many enhancements and new features but some users have reported difficulty deleting PDF files. A similar issue also happened in Windows 8 and only affects PDF documents, all other file formats remain unaffected.
When a PDF is highlighted in Windows explorer and deleted the following dialog appears:
The issue only seems to affect some users after upgrading to Windows 10 and the preview pane in file explorer is active. The Preview pane is optional and can be toggled on and off using Alt + P or left off permanently, but it is very useful if you work with a lot of files.
The best work around is to hold shift and then press the delete key on the keyboard, this will delete the file permanently so some caution is needed. Another option is to turn off the preview pane and delete the file.