All USB Downstream ports are disabled on a EHCI Host Controller after restart or inserting a USB device on Windows Vista or Windows 7

These USB devices were likely produced prior to the release of Windows Vista and Windows 7. Therefore are not certified for these operating systems, and are non-compliant to the USB 2.0 specification. These devices may not work correctly with some AMD systems with built in EHCI Host Controllers.

Flash devices known to cause this condition with AMD systems but could also affect other systems are:

• Toshiba Model # U2M-016GT
• Kingston Model DT 4G

Technical details:
USB 2.0 non-compliant devices connected to a EHCI Host port can generate what is termed as a "babble condition" (where the device continues to talk outside of its frame). As a result, the host controller detects the Babble condition and disables the offending port. However, if the Babble condition happens at the end of the Frame, due to a Host Controller logic issue on some AMD systems, the Host Controller also disables all other downstream ports within this controller. 

Example: In AMD Hudson 1 based systems there are 5 (five) ports per EHCI controller. If a Babble condition is detected on port 3, then all five ports, port 0 to 4, are disabled by the Host controller.