Hey all. I have recently done a clean install of windows 7 on my Lenovo Ideapad 500s-151SK Laptop. Everything seems fine during the installation process. However, none of the USB ports seems to be working after the installation. In Device Manager, I noticed that there are yellow signs indicating the USB drivers are not installed. I tried to manually install the drivers but it didn't work at all. I have a USB full of the relevant drivers needed to install, but I cannot do anything since none of the ports is working. Could you guys give me a hint on how to fix the problem?