One of the most common hardware problems is too hot system.
If your computer:
1. Works fine at the start, but after 20min slowdown significantly,
2. Feels now a lot slower than in the past,
3. Restarts occasionally without warning,
You might have hot CPU. Waaay HOT.

Let’s analyze !
Latest PCs will have temperature sensors built in their system at various spots. All we need to do is get the information they receive, and see if they’re in the normal temp range.

Many programs does it, but my recommendation will be CPUID HWMonitor.
It is portable program (no installation required), and consider to be compatible with most hardware models.

After running it we’ll see the reading of each sensor that located in our system (CPU, GPU, Harddrive, NB).

Normal Idle (nothing running in the background) temperatures:
Intel Pentium 4 series: 45c
Intel Pentium D series: 50c
Intel Pentium Dual-Core series: 50c
Intel Core 2 series: 60c
Intel Quad series: 65c

AMD Athlon64 series: 40c
AMD Athlon64 X2 series: 50c
AMD Phenom series: 50c
AMD Phenom II series: 50c

If your temperatures are exceeding those in the list in more than 15c, you’re in a risk.

There are many ways of dealing with high temperatures -

Cleaning your case and CPU cooler from dust:



Replacing the thermal grease:

Replacing the stock CPU cooler: