XLS vs. XLSX

cyberdyne · #1 11-24-2010, 10:45 AM

Hi,

I am using Office 2010 on a Win7 system.

I've been sent 4 attachments, 3 x .XLS and 1 x .XLSX, by email, via my client Thunderbird 2.

The .XLS attachments open without issue but the .XLSX attachment, after running Excel automatically (I had to associate these files with Excel via Thunderbird), presents a warning message about possible corruption and ask if I trust the source.

What is causing this and can this message be suppressed please?

Thank you

Kaneto · #2 11-24-2010, 11:41 PM

This sounds like a case of Excel's Extension Hardening, which was introduced in version 2007. Does the error message say that the file is in a different format than specified by the extension?

Some more info on Extension Hardening and how to disable it can be found here:
http://blogs.msdn.com/b/vsofficedeve...n-warning.aspx

Hope this helps.

-SW

cyberdyne · #3 11-25-2010, 01:04 AM

Quote:

Originally Posted by Kaneto

This sounds like a case of Excel's Extension Hardening, which was introduced in version 2007. Does the error message say that the file is in a different format than specified by the extension?

Some more info on Extension Hardening and how to disable it can be found here:
http://blogs.msdn.com/b/vsofficedeve...n-warning.aspx

Hope this helps.

-SW

Yes, it does. I'll have a read of your link.
Thank you.

cyberdyne · #4 11-25-2010, 01:12 AM

Quote:

Originally Posted by cyberdyne

Hi,
.......//.. can this message be suppressed please?

Thank you

Quote:

Client Configuration of Extension Hardening
Client desktops can change the default behavior of the security check using a registry key. The following registry key can be set to alter the behavior of the Excel 2007 client in the following ways:

Key: HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\E xcel\Security
Value: (DWORD)"ExtensionHardening" = [0 = Disable check; 1 = Enable check and prompt; 2 = Enable check, no prompt deny open]
Default setting if value not present is 1 (enable and prompt).

Posting what I hope is the workaround to my own question.
Thank you for pointing me in the right direction.

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