**** Create a backup of your files before continuing below ***
Batch convert .doc to .docx (and equivilent for other office formats)
1: Download the Migration Manager kit and extract it into a new folder ex: C:\office.
\Software Distribution\Microsoft\Office\Convert doc to docx\MigrationPlanningManager.exe or click HERE
2: Install the Office Pack - this step is required even if you have Microsoft Office 2007 or later installed on your computer.
\Software Distribution\Microsoft\Office\Convert doc to docx\FileFormatConverters.exe or click HERE
3: Assuming that you extracted the Office Manager files in c:\office directory, go c:\office\tools, open ofc.ini using notepad and add the following line.
4: Open command prompt and go to c:\office\tools. Type ofc.exe, hit ENTER
5: All old Office files in that folder (and sub-folders) will get converted (replaced) to the new format and are saved in a new folder.
This utility works with Word (doc to docx), Access databases, PowerPoint (ppt to pptx),
Visio diagrams, Excel (xls to xlsx) and Microsoft Project files. The conversion will not convert password protected documents.