High Cpu Usage on Windows 7

Hello mates,

I've been using windows 7 home basic 32bit. my laptop cpu usage is always full since last two months. It's getting worse everyday. I can't even watch a hd movie. typing also getting slow. i've tried many antivirus(trial versons), and installed zone alarm firewall. scanned with some cloud based antivirus also.

I can't find any virus. sometimes malwarebytes anti malware alerted inbound traffic to svchost.exe on multiple ports. (i ve scanned scvhost.exe on virustotal. The result said it was clean.

someone help me please