You can use this free utility to archive IIS logs for multiple websites. This is a very useful tool when you want to keep your web servers disk free of old IIS logs.
You can use it as you like. You can download both source and binaries.
System Requirements: x86, .NET 1.x or above, Window OS
Binaries - IIS Logs Archiving Utility Binaries.zip
Source - IIS Logs Archiving Utility Source.zip
Disclaimer: The software provided is as-is. Use it at your own risk. You are free to modify the code as you like.