Processes that dominate the CPU cause high CPU usage. These programs are either genuine or prohibited. Unwanted programs include viruses, spyware, ActiveX and Windows registry errors, Trojans and other malware.
Spyware includes software used for marketing that gathers information on online activities of a user. They alter the settings of machines and cripple machine operations.
Malware includes worms, spooler, constructor, denial of service attacks, backdoor and IM-flooder. On the other hand, Trojans include Proxy, Arc-bomb, Clickers, SMS, IM and Spy.
Opening a large number of allowed processes also causes high CPU usage. Genuine programs, such as Microsoft software, result in high CPU usage when they are processor-intensive applications.
Viruses and malware slow down the CPU by generating numerous processes that require much computing power.
In contrast, Trojans bog down the CPU searching for financial information. They make the devices and services engaged abnormally. Worms duplicate and destroy information. They consume system files and user files.
The CPU’s normal usage ranges between 2 to 7 percent when it is idle. Higher usage comes about from the reasons above. Eighty to 90 percent operation of the CPU causes applications on the machine to become sluggish or halt. The Task Manager gives details of the processes utilizing the CPU.