JSI Tip 1970. Network seem a little sluggish with SP4, SP5, SP6(a)?

Starting with SP4, RDR.SYS was changed to fix a problem. This causes some additional network traffic.

Use Regedt32 to navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Rdr\Parameters

Edit or Add Value name FileSystemControlFilter as a type REG_DWORD. In the DWORD Editor, set the data value to 0.

The default is 1, which filters FSCTL_IS_VOLUME_MOUNTED.

This will be fixed when SP7 becomes available.

There is a current hotfix available, if you call Microsoft and mention fix Q249799.