Before you try this, make sure that the 'Task Scheduler' service is set to 'Automatic startup'.
Try one thing, download
Bootvis. Insall and run it. Now go to the Trace menu and click 'Next boot + driver delays' and click OK. The system will reboot. After the reboot is complete, Bootvis will start automatically and display the results. Now go to Trace->Optimize system and let it reboot again. After Bootvis has done its job, the problem should be sorted out.