aymen11531,
On behalf of Tom's Moderator Team, welcome aboard!
The problem you've described is very common. Aside from a properly mounted and functioning CPU cooler, factors include ambient temperature, and how different users define the term "idle".
Just so you know, the International Standard for "normal" ambient (room) temperature is 22°C or 72°F. Obviously, for every degree ambient is above normal, so will be your idle and load Core temperatures.
The definition of "idle" is minimum activity at 1% CPU Utilization. If "idle" is really
idle, then with your Cooler Master 410P and normal ambient temperature, the Cores should idle at about 2 Watts on a 3rd generation processor, with Core temperatures below 30 °C in a well ventilated case, just as you mentioned. Here's how idle power consumption (Watts) should look:
Low idle power consumption produces low Core temperatures.
If "SpeedStep", also called EIST (Enhanced Intel SpeedStep Technology), is disabled in BIOS, or Windows Power Options is set to “High Performance”, then depending on Vcore and Core speed, idle Power can exceed 30 Watts, which will result in high idle temperatures, especially when combined with high Ambient temperature.
SpeedStep and all "C" States must be enabled in BIOS. Also, if Windows Power Options for "Balanced" or "Power saver" is not set correctly, then SpeedStep will not work ... OR ... if Windows Power Options is set to "High performance", then SpeedStep will not work because Minimum processor state can‘t be set.
To check this, go to Settings > System > Power & sleep > Additional power settings > Change plan setting > Change advanced power settings > Processor power management > Minimum processor state. The default setting is 5%. If it's not, then correct it and click Apply.
If BIOS and Windows are indeed set up properly, then the problem points to excessive software activity. "Idle" means no programs or screensaver running, and off line. No Dropbox or Folding or SETI or "tray-trash" running in the background, and just
1 or 2% CPU Utilization under the "Performance" tab in Windows Task Manager. Here's how idle should look:
If you don't have low CPU Utilization at idle, then your processor can't reach low Core temperatures.
Check the "Process", "Startup" and "Services" tabs in Windows Task Manager to find unnecessary and excessive software activity. Often, users encounter the problem you described due to software which was installed or a Windows Update that coincides with when the problem was first noticed.
Once again, welcome aboard!
CT