You can find LSP sample in windows SDK at location
"(Drive Letter)\Program Files\Microsoft SDKs\Windows\v7.1\Samples\netds\winsock\lsp" if you have 7.1 Microsoft SDK.
If you have Vista SDK then it will be at location "(Drive Letter)\Program Files\Microsoft SDKs\Windows\v6.1\Samples\NetDs\winsock\LSP"
Windows SDK can be downloaded from Microsoft site
http://www.microsoft.com/download/en/details.aspx?id=8279[
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