I have a Dell Inspiron laptop that on Sunday while I was using it mysteriously shut off and then rebooted and when it came back on instead of getting a log in screen to log into windows it just has a black screen with a white cursor. The computer is running Windows Vista. I was on facebook at the time it did this and I also was using my iPhone as a hotspot via usb cable. I am also having this same issue with my Dell all-in-one desktop computer which is also running Vista. It mysteriously did the same thing on Saturday. It was having other issues prior to the black screen that I was getting help with so when my laptop ended up having the exact same black screen with cursor instead of log in screen I was confused since it wasn't having the other issues the other computer was having prior to it happening to it. I am getting help for that computer on TechSpot. Could my iPhone have a virus or something that transferred to my desktop and then my laptop via the usb cable? Any ideas or suggestions would be greatly appreciated...Thanks!