Windows 7: CPU going up to 100% for no reason.

So this is my uncle's laptop, and he said his laptop have been slow for quite a time, after I scanned his laptop by microsoft security essentials, didn't find anything bad, and the cpu is still 100%, here's the screenshot for it. Hope some could find a problem for me

Here is a grate place to start. It has helped many.
Optimize Windows 7

Open Task Manager, click 'Show processes for all users' then click CPU tab to show highest at the top of the list.

Welcome to the forum,

This may help as well,

Troubleshoot Application Conflicts by Performing a Clean Startup

Your post doesn't really tell that much apart from your uncle using MSE as the AV.
The posts above are really good but rather than go straight in with "optimising this and that" l would start off with the basics first.
If you haven't got them already, download the following free software -
CCleaner
Glary Utilities 1 click maintenance
SuperAntiSpyware
Malwarebytes
I'm not sure whether l'm allowed to post links to these but you'll find them via google anyway.
Before you run each one, check for their updates first.
Once you've run them, and they have "done their thing", you can either choose to keep them, which is
advisable, or you can remove them via the control panels remove programs option.
Then go to start, type in msconfig, and select the msconfig entry.
When you get the System Configuration Panel up, select the startup tab. The only tab that really needs to be ticked for now is your AV. Uncheck all others, select ok, and you'll probably need to reboot.
After all of that, then see how your uncle's laptop goes!

Thanks for all the replies , I will eventually try every single one, and here's the process list after I click on the "show processes for all users", and there are bunch of svchost.exe .. and thats the process which the problem came from I can tell..

You don't need a bunch of programs to start off with...The bolded part above is a good start, which is also mentioned in the tutorial I linked above.

Troubleshoot Application Conflicts by Performing a Clean Startup

Malwarebytes free is a good malware scanner,

Malwarebytes : Malwarebytes Anti-Malware removes malware including viruses, spyware, worms and trojans, plus it protects your computer

Well we are all getting to the same pond using different roads. Looking down all the roads and I was the OP I would choose this road. Posted by derekimo.
Troubleshoot Application Conflicts by Performing a Clean Startup

Ahh, I think the problem came from svchost.exe though..

Totally agree with you Derek, wasn't trying to be awkward and l've even used the links you suggested myself.
What l was trying to say was that because there may be a load of cr*p on the computer, as this would definitely slow it down, l would have gone with my suggestions first and then followed up with the remainder of your lists as it may save time. Just a thought?
Just to digress, surely the svchost.exe entries that Kevin is worried about are sort of irrelevant as they do not show what dll libraries are bundled up within each one. Therefore it boils down to tailoring the up and running services.
I'd still go with just a clean up first, as well as the msconfig file adjusment, and then post back screenshots after that.
Kevin is obviosly going to try everything out, so we'll see how it goes
Regards