When ISAPI and CGI application hosted on IIS 6.0 on Windows Server 2003 send responses, you experience slow performance.
NOTE: These same applications perform properly when hosted on IIS 5.0.
This behavior is the result of a default buffer size for sends that is too small.
NOTE: You must install SP1 (Service Pack 1) for the resolution in this tip to work.
To resolve this performance issue:
1. Open a CMD.EXE window.
2. Type the following commands, pressing Enter after each line:
REG ADD HKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters /V MaxBufferedSendBytes /T REG_DWORD /F /D 65536