iisnode faq

Accessing iisnode samples after installation on a 64 bit Windows system fails

iisnode is a 32 bit module and requires the application pool in IIS on a 64 bit Windows system to explicitly allow 32 bits modules. Check the advanced settings of the application pool running the Default Web Site in your IIS installation to ensure it allows loading of 32 bit modules.

Does iisnode block threads per request or connection

iisnode is completely async and does not block threads per request or connection. It does allocate small amounts of memory for active requests.