The locations of the registry files in Windows 2008 R2

In Windows XP

For HTTP:

HKEY_CLASSES_ROOT\http\shell\open\command

The format is like this:

HKEY_CLASSES_ROOT\[prot]\shell\open\command

where [prot] is the protocol (HTTP, FTP..)

In Windows Vista

For HTTP:

HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell\Associations\UrlAssociations\http

The format is like this:

HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell\Associations\UrlAssociations\[prot]

where [prot] is the protocol (HTTP, FTP..)

For more in depth info see this link.

This should be configured through GPO by applying a throttle rate to all source IP addresses associated to the card. See http://www.microsoft.com/downloads/details.aspx?FamilyID=59030735-8fde-47c7-aa96-d4108f779f20&displaylang=en for a detailed explanation.