Are you 110% positive that it was MSE that caused this? I have seen various reports that many 3rd party applications can cause this as well.I installed the version for WIn7 but I couldn't figure out why my CPU fan high speed kicks in and just stays on. When I checked the Task Manager, there are 13 instances of explorer.exe. This keeps happening even on a fresh installation. I have no issues with WinXP though.