Wrong CPU Temp Reading

[tatar5355]

Speccy(program that i use for measuring temperature) shows 99 degree.Actualy its seems about 30-40 degree, i mean not that hot.I had performance issue with this case.Also, fan running at top speed.Could you please help?

 

[C12Friedman]

Temperature readings inside a PC are not directly measured but are instead interpolated by software, try SpeedFan or CoreTemp or... see what they tell you

 

[tatar5355]

 

[C12Friedman]

At least SpeedFan isn't reporting 99°C, but your TjCase (also known as TjMax or Thermal Junction) is 90°C which is the temperature at which CPU damage can occur, the PC will begin to throttle itself and look for processes it can close in an attempt to lower it's temps (ironically, that takes resources which sometimes causes more heat). I'm going to suggest checking your CPU cooler to ensure it hasn't come loose at one (or more) of the corners.
I am assuming this is an All-In-One or Small Form Factor PC, what make and model? How old?