symptoms in laptop
1. gets heated fast (fan is running slow; speed fan doesn't recognise fan)
2. yotube/facebook videos not running properly.
3. in task manager CPU usage history is almost 100% for two cores
4. laptop crashes abruptly sometimes
5. graphics breakdown often
6. very slow working
"3. in task manager CPU usage history is almost 100% for two cores"
It's likely that your item #3 is responsible for your other five issues.
In Task Manager, click the "Processes" tab, click the "Show processes from all users" button then click on the "CPU" column-heading to sort the list so that the busiest processes are at the top. Ignore "System Idle Process" as that's the opposite of busy. You should then be able to identify the rogue process(es) so post the name(s) here and I'll see if I can come up with a resolution.
That's very suspicious as it looks like it could be malware masquerading as a legitimate Windows system process.
Back in Task Manager, right-click that process and choose "Properties". What does it show for the "Location". Note that you may need to drag the Task Manager window over to see the Properties window behind it.
Unfortunately you can't attach images or other files to your posts on this forum although you could upload an image to a file-sharing site and post the link to it here.
PS: Just in case your PC is infected, I wouldn't recommend leaving it another two weeks before you reply ;)