Symptoms
PDF, MS Word, MS Excel, MS PowerPoint, etc documents are saved or shown as pdf_auto_file, doc_auto_file, xls_auto_file, docx_auto_file, xlsx_auto_file, ppt_auto_file. No default application is assigned to open them.Also, they may be shown as PDF file, DOC file, XLS file, PPT file instead of Adobe Acrobat Document, Microsoft Word Document, Microsoft Excel Document, Microsoft PowerPoint Document.
Cause
Such issue may happen when the file type was registered in Windows before the default application for this file is installed. actually only the last one.This may happen due to sharing applications from Mac side.
Resolution
1. Please open Registry Editor (Start > Run... > type regedit > click OK )2. In the Registry Editor please expand HKEY_CLASSES_ROOT and find appropriate file extension and click it. For example, for PDF files - .pdf
3. In the right pane right-clcik on (Deafult) and select Delete. The value pdf_auto_file will go away.
4. Close Registry Editor
5. Go to Start -> Control Panel -> Folder Options. Open tab File Types.Below
6. Find PDF extension in the list. Filetype will be either pdf_auto_file or PDF File. The default file type (Adobe Acrobat Document) is mentioned below. Click Restore button.
7. Make sure that default application (Adobe Reader) is defined for this file extension. Now all files should be shown correctly.
8. Repeat the same for all other needed file types (.doc, .xls, .ppt, .docx, .xlsx, .pptx)
The Windows Vista tool you use to change file associations in located in the Control Panel under the Default Programs icon:

Once on the Default Programs screen you have two choices for changing file associations:
- Set your default programs
- Associate a file type or protocol with a program



The second selection on the Default Programs screen is Associate A File Type Or Protocol With A Program. On this screen of the tool, you get a very long list of file extensions, including a description and the name of their associated program if it is known. To modify the program associated with a particular extension, you select the extension and click the Change Program button.


Note: that it is generally not a good idea to associate a file extension with a program that is not capable of reading or otherwise acting on it.
