Windows CE guarantees support for connecting hub devices only up to one level deep. In laboratory settings, the HCD module supplied by Microsoft has supported several layers of nested hubs; however, this feature could not be thoroughly tested and certified before the release of Windows CE 2.10. OEMs who want to support multiple layers of nested hubs are strongly encouraged to test the behavior and power consumption of peripherals thoroughly under a wide variety of hub configurations before announcing support for multiple levels of hubs in their products.