Windows launches this twice on startup, which causes some problems like I can't open windows update. Without ending both of the tasks and starting a new explorer through 'Run' so only 1 instance is running, I can't get to windows update. Any fix on this?

Have you checked in all start up menus to check that explorer.exe hasn't been added in additional to the default one

It hasn't happened for at least two days now i'm hoping it stays that way. Turns out the two explorer.exe's were because I had the windows explorer and the taskbar as seperate processes.

One thing I notice is that on my machine ever explorer process uses 30MB, on occasion i will have an issue where I cannot open "my computer" and file operations freeze (sits endlessly increasing the progress bar at the top of any window) I noticed that when that happens the offending explorer is 37MB. If i end it then everything returns to normal. I too have "open explorer windows as a separate process" option. So there is definitely something with that, however I had this issue on occasion under vista as well. SO who know what could be the culprit.