Recently I discovered a new an interesting way to lock up the W3WP process. I was trying to deploy a content type including a document template all in one feature. Because I was declaring fields (and a workflow too) I had to set the scope of the feature to Site. The problem is that files are supposed to be provisioned via <Module> tags — in a Web scoped feature. I didn’t think much about it until I realized that whenever I activated or deactivated the feature I’d lock up whatever process that was doing the work. So if I did it through the web W3WP would end up in an endless (or seemingly endless) loop. Similarly doing it from the command line caused STSADM to lock up.

So if you’re locking up the worker process (as evidenced by 50% or 100% sustained processor utilization) you may want to make sure you don’t have a <Module> tag in your Site scoped feature…