When installing for IIS 7.x, please choose x86 flavors for installation on 32-bit Windows systems, and amd64 flavors for installation on 64-bit Windows systems.
When installing for IIS Express, please choose x86 flavor regardless of the bitness of your OS (IIS Express only ships 32 bit version currently).
iisnode is completely async and does not block threads per request or connection. It does allocate small amounts of memory for active requests.
Please verify if your issue is already known by searching https://github.com/tjanczuk/iisnode/issues. If you don't find it there, create a new issue report. Please include the following information with your bug report:
If you run into a 503 status code with IIS reporting error code 0x5 (ERROR_ACCESS_DENIED), make sure the identity of the application pool running the site that hosts your node.js application has read & execute rights to node.exe on disk. If you are using the default IIS configuration (DefaultAppPool running under ApplicationPoolIdentity), you can set appropriate ACLs on the node.exe by running:
icacls %systemdrive%\node\node.exe /grant IIS_IUSRS:rx
build\debug\%PROCESSOR_ARCHITECTURE%\iisnode.msifrom an administrative command line