ArcView 3.x on XP Service Pack 2 is slow when reading files across a network

Description

After installing Service Pack 2 for Windows XP (SP2) and/or Microsoft security patch MS04-44 (KB885835), ArcView 3.x clients' reading files hosted on network file servers may experience very slow response times. This problem is most noticeable when reading very large amounts of data, or a large number of files concurrently across the network.

Cause

This is caused by some aggressive file locking introduced with Microsoft Security Update KB885835. The files are locked (closed) before ArcView can generate a sufficient buffer for tasks such as panning.

Solution or Workaround

Warning:
The workaround given below requires editing the registry. Before editing the registry it is recommended that you make a backup of the registry and know how to restore it. For more information about how the registry works see Microsoft Knowledge Base article #256986.

ESRI does not assume responsiblilty for errors resulting from executing the procedures described in the article. Proceed at your own risk.

1. Follow the instructions described in the Microsoft Knowledge Base article #822219 in the bullet called: "Disable opportunistic locking on the client..." It requires making changes to the registry.
   Note: It is necessary to create a new DWORD value for “OplocksDisabled" if it does not already exist in the registry.
2. After editing the registry, reboot the client machine.
3. Test the results by reading some large shapefiles across the network. Display time while accessing the shapefile across the network should return to the speed experienced before the SP2/MS04-44 update.