|You didn't tell us you have a laptop, that's important. How about posting the make/model? Did you check Device Manager to see which program is using 100% of the CPU?|
"what should i do if my system is infected ????"
What do you normally do? Boot into safe mode & run a FULL (not quick) scan for viruses & malware. Which anti-virus program do you have? For malware removal, I suggest Malwarebytes Antimalware. You can use the free version:
And if you don't use a cleaner, I suggest you download, install & run CCleaner-Slim & use it regularly. On the left side, you can check off what you want or don't want cleaned. You can also use it to clean the Registry, to Uninstall programs, & to manage your Startup apps. Get it here (make sure to get the Slim version):
These are all things you should be doing as part of normal system maintenance.