When the Office 2007 Compatibility Pack Service Pack 1 is installed, you cannot open an encrypted Office Open XML file that contains a macro in Office 2003

When the Microsoft Office 2007 Compatibility Pack Service Pack 1 is installed, you cannot open an encrypted Office Open XML file that contains a macro and that has one of the following extensions in Microsoft Office 2003:

• .xlsm
• .docm
• .pptxm

This behavior does not occur for files that are saved in the "Microsoft Office 97 - 2003" file format.

Note An encrypted file is a file that you protect by using any of the following methods:

• Password protection
• Information Rights Management (IRM)
• Workbook protection in Microsoft Office Excel 2007

To resolve this problem, you must install the hotfix that is described in KB958703, and then you must disable antivirus scanning on encrypted files that contain macros.

How to obtain the hotfix

This issue is fixed in the 2007 Office system hotfix package that is dated October 28, 2008. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

How to disable antivirus scanning on encrypted files that contain macros

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: Warning This workaround may make a computer or a network more vulnerable to attack by malicious users or by malicious software such as viruses. We do not recommend this workaround but are providing this information so that you can implement this workaround at your own discretion. Use this workaround at your own risk.

To work around this issue, disable antivirus scanning on encrypted files that contain macros. To do this, follow these steps:

1. Exit the 2007 Office programs.
2. Start Registry Editor.
   • In Windows Vista, click Start
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     , type regedit in the Start Search box, and then press ENTER.
     
     
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     If you are prompted for an administrator password or for confirmation, type the password, or provide confirmation.
   • In Windows XP, click Start, click Run, type regedit in the Open box, and then click OK.
3. Locate and then click one of the following registry subkeys as appropriate:
   • HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Excel\Security
   • HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\PowerPoint\Security
   • HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Word\Security
4. On the Edit menu, point to New, and then click DWORD Value.
5. Type one of the following value names, depending on the registry subkey that you selected in step 3, and then press ENTER:
   • ExcelBypassEncryptedMacroScan
   • PPTBypassEncryptedMacroScan
   • WordBypassEncryptedMacroScan
6. Right-click the DWORD value that you created in step 5, and then click Modify.
7. In the Value data box, type 1, and then click OK.
8. Exit Registry Editor.

Note The steps above should not be used after Office 2007 SP2 has been installed. This registry information is also provided in the '2007 Microsoft Office Security Guide', but that documentation was created prior to the release of the Office 2007 Service Pack 2.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.