I upgraded my Lenovo laptop to windows 8.1 last evening. All my usb devices stopped working. I noticed the chipset had the yellow triangle on it and found out the driver was not digitally signed so Win 8.1 blocked it. I managed to disable the feature that checks for driver signing and now the chipset is good, however my mouse, webcam are both dead with the yellow triangle and if I try to reinstall or update, I just get "invalid data". Any ideas?