Microsoft Word: "Attempting to open a file created in earlier version"

I was working in Microsoft Word 2003.  I tried to open a .doc file.  It may have been originally written in WordStar, XyWrite, WordPerfect for DOS, or some other word processing program.  Word gave me an error message:

You are attempting to open a file that was created in an earlier version of Microsoft Office. This file type is blocked from opening in this version by your registry policy setting.

Of course, this was not what I wanted to hear.  I did a search and found a Microsoft webpage that, for my purposes, led to another webpage that led me to four REG file downloads whose contents I combined in a single REG file that I named MicrosoftOfficeUnblock.reg, whose contents were as follows:

Windows Registry Editor Version 5.00

; Unblock Word

[HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Word\Security\FileOpenBlock]
"FilesBeforeVersion"=dword:00000000

; Unblock Excel

[HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Excel\Security\FileOpenBlock]
"LotusandQuattroFiles"=dword:00000000
"LegacyBinaryFiles"=dword:00000000
"LegacyDatabaseAndDatasourceFiles"=dword:00000000
[HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Excel\Security\FileSaveBlock]
"LotusandQuattroFiles"=dword:00000000
"LegacyBinaryFiles"=dword:00000000
"LegacyDatabaseAndDatasourceFiles"=dword:00000000

; Unblock PowerPoint

[HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\PowerPoint\Security
\FileOpenBlock]
"FilesBeforePowerPoint97"=dword:00000000
[HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\PowerPoint\Security
\FileSaveBlock]
"FilesBeforePowerPoint97"=dword:00000000

; Unblock Corel Draw

[HKEY_LOCAL_MACHINE\Software\Microsoft\Shared Tools\Graphics Filters\Import\CDR]
"Enabled"=dword:00000001

I ran that REG file and also added its contents to my Win7RegEdit.reg file, along with a reminder to run that file both early and, again, late in the process of installing Windows 7.  The REG fix appeared to work without a need for a reboot; I was immediately able to open files in Word that were blocked just a few minutes earlier.