I have Win 7 and have been using this USB 2 extension to help with the extra external hard drives I have. No problems. I can't boot up with all the different Ext Hard Drs, so after I on I turn a power strip which includes this USD ext.
Works fine for me with Windows 7. I guess the best thing I could say about it is that it sits behind my computer and monitor and acts justs like I have a lot of extra USB ports on the computer and I don't even think about it being there.