Microsoft KB Archive/172705

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Explorer Access Violates When Viewing a File's Properties

Article ID: 172705

Article Last Modified on 11/1/2006



APPLIES TO

  • Microsoft Windows NT Server 4.0, Terminal Server Edition
  • Microsoft Windows NT Workstation 4.0 Developer Edition
  • Microsoft Windows NT Server 4.0 Standard Edition



This article was previously published under Q172705

SYMPTOMS

When you use Windows NT Explorer to view the properties of a file, an access violation occurs. If Dr. Watson is installed, it gives the standard AV pop-up error message, for example:

An application error has occurred and an application error log is being generated.

Explorer.exe
Exception: access violation (0xc0000005), Address 0x77f64b53

CAUSE

This error can be caused if a file's property set has a corruption. In this case, the thumbnail for the file had an empty Binary Large Object Bitmap (BLOB) stored in the place of a CLIPDATA structure. Because Windows NT Explorer expects the serialized CLIPDATA to have a minimum size of 12 bytes but finds the empty BLOB to have only 8 bytes, it concludes that the discrepancy must be caused by data corruption and exits with the above error. During the exit, Windows NT Explorer cleaned up the allocated *CLIPDATA structure, but in so doing tried to free CLIPDATA.pClipData, which hadn't been allocated at the point of the failure.

The fix now zero initializes the CLIPDATA structure after allocation.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

152734 How to Obtain the Latest Windows NT 4.0 Service Pack




STATUS

Microsoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.



Additional query words: prodnt

Keywords: kbhotfixserver kbqfe kbbug kbenv kbfix KB172705