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Article ID: 2570623 - Last Review: July 12, 2012 - Revision: 12.0

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After you install MS11-021 and the Office File Validation (OFV) Add-in for Microsoft Office 2003 (KB 2501584 (;en-US;2501584) ), workbooks stored in a network location open more slowly over the network in Excel 2003 than they did without the OFV installed. The decrease in performance depends on the size of the workbook and bandwidth of the network, and in some scenarios, can seem to cause Excel to crash. 


To resolve this issue, download and install the Office 2010 File Validation update from the following Microsoft Knowledge Base article:

2553065  ([anySimpleType]/ ) - Description of the Office 2010 File Validation update: September 13, 2011

If you find the performance of files over the network is still not satisfactory after you install the update, the "Workarounds" section identifies the various options that you can try. 


Method 1: Upgrade to Excel 2010 or Excel 2007

Method 2: Copy the file to the local computer

Method 3: Disable the OFV Add-in by removing the Excel part of the OFV

Method 4: Disable the OFV Add-in by using a registry setting

More information

Office 2010 and Office 2007 are not affected because they include a new feature for opening files over the network that copies the complete file locally first and then scans the file by using the OFV so that the file reads do not include the network traffic.

To help protect your computer from risk, we recommend that you do not open files that you receive as email message attachments, especially if the messages arrive unexpectedly. Additionally, do not open files that you receive as attachments if the files are from a person who is unknown to you.

Applies to
  • Microsoft Office Excel 2003
kbfixme kbmsifixme kbsmbportal KB2570623
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