File conversion error word 2003 - Microsoft Office Word 2003 for PC

SOURCE: word 2003 can not open

You may receive the following error:

Word cannot start the converter mswrd632.wpc
This error is cause because of f the security update for Windows XP, Windows 2000, and Windows Server 2003 on December 8, 2009.
You may experience mail merge issues write files are parsed but no message is shown.
To resolve this issue, an affected user can unregister the mswrd632 converter by editing the registry as follows:
Click Start, click Run, type regedit, and then click OK.

Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Text Converters\Import\MSWord6.wpc
On the Edit menu, click Delete.
Click Yes.
Exit Registry Editor.

NOTE: For x64 systems above path is slightly changed:
HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Windows\ CurrentVersion\Applets\Wordpad
This change will effectively unregister the converter and disable it for third-party applications and for Microsoft Office. Microsoft Office will use its own text converters to open these kinds of files.
You can also fix this issue with applying the registry fix, but that is a less secure way according to Microsoft, as this fix actually creates 'AllowConversion' key in the new 'Wordpad' subfolder. (HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Applets\Wordpad)
Download REG fix
There is another way to solve this issue by copying the MSWrd632.wpc file from another computer that doesn't have this issue. Make sure that this file comes from a trusted source on your network. This file can be found on the following path:
C:\Program Files\Common Files\Microsoft Shared\TextConv










OR

Go to Tools > Options > General (Tab) in Word 2003
And check "Confirm Conversion at Open"
When you next try to open the document it will prompt you with a list to convert from. Choose Word 2007 and your document will open.
Have in mind that you will have to unregister mswrd632 first, which is noted above, before you make this changes.
NOTE: If none of this works, please check that your file is not corrupted, or that you or someone else didn't add X at the end of .doc extension or vise versa. This WILL NOT work! You have to convert the document using Office 2007 or 2010.

SOURCE: Word 2003 opening .doc error

Your post says "File Conversion" - what type of file are you trying to open? If it's a .docx file from the Word 2007 version, you can download a file converter from Microsoft here:
http://www.microsoft.com/downloads/details.aspx?FamilyId=941B3470-3AE9-4AEE-8F43-C6BB74CD1466&displaylang=en