I want to start off by stating that about 4 months ago I had this same problem with my computer where my explorer.exe would not automatically run when i boot my pc up. After manually running explorer it would stay "not responding" for ~15-20 min there after and I couldn't even use the pc during that time. This was when I was running Windows Vista.
I fixed the problem by doing a clean install with Windows 7 and mostly everything was smooth, until this morning.
I boot my pc and up popped an automatic update from logitech for my keyboard/mouse software (new setpoint application). So I installed it and was recommended to restart my pc.
So I restarted it and walked away for a second only to come back and see a black screen, I knew right then that the problem occurred again. I had to manually boot up the explorer and wait ~20 min for it to start responding.
I ran a system restore to the night before and it removed the newly installed setpoint program but still had the explorer problem.
This may come to some help. Even though I never had explorer.exe problems prior to this with windows 7, my internet doesn't start working until about 15-20 minutes before I boot my computer up either, it's almost like there is a hold somewhere in my system. It runs fine on other computers on the network, however, my pc seems to have that 15-20 min no response time on the internet.This problem has been happening for weeks. I will ask about this problem in another post however I figured it may help to fix my problem.
Thank you in advance