Windows Vista is our operating system. So this evening I decided to install a webcam that my sister gave me. Towards the end of the installation, AVG popped up an alert saying something to the effect of "make sure you know where this program is coming from, it may be harmful." I've seen similar messages often and since I knew it was part of the camera installation, I chose to proceed and restart my computer for the changes to take effect. Now I am completely unable to log on to my computer. System Repair runs upon startup and doesn't find anything. I've tried System Restore on 4 different restore points but get an error message each time saying it is unable to restore. I'm lost as to what to do. You guys have always been great in the past and I have recommended several of my friends to you! Look forward to hearing from you.