Windows 7: CPU Hike to 100% Everytime.

I am having Dell Vostro 1015. I am having 4GB RAM and 32-bit windows 7 installed on my laptop. My CPU hike to 100% though I don't use anything. I have just installed 2GB RAM 15 days ago and new HDD, So is it the reason for this? I am attaching my task manager's all services snapshot. Kindly help me with this. I have already checked for viruses but I found nothing. I am copying through Tera Copy, then task manager shows it is the highest memory user and If I am using Chrome, then it shows Chrome is highest user of memory. And if everything is closes, then also CPU 100%.

Resource Monitor may be able to give you a better understanding of why your CPU usage is so high. You might have a malware scan going on, or perhaps a scheduled disk defrag while the computer is idle.

Resource Monitor

You could also give this free utility from Microsoft a try. It's called Process Explorer and gives a much deeper look into what's using your CPU. You don't even have to install it. You can simply run it in your browser. There's a link for Proces Explorer in this "How-to" article.

Process Explorer

This Microsoft forum thread also has some suggestions on how to isolate the high CPU usage.

My CPU usage is at 100%, but task manager says nothing's using - Microsoft Community

I am uploading process explorer file. Kindly look at it.

You have several processes for Chrome.

Why Does Chrome Have So Many Open Processes? - How-To Geek

And several process that belong to Quick Heal including SCANWSCS.EXE, QUHLPSVC.EXE, ScSecSvc.exe, OPSSVC.EXE, ONLINENT.EXE. I'm guessing that Quick Heal is your installed security suite. You might consider using a less resource intensive product like Microsoft Security Essentials or Avast both of which are free.

You've also got Tuneup Utilities which is a 3rd party "optimizer". Windows 7 really doesn't need these tools because they tend to do more harm than good. Microsoft includes it's own "optimizing" tools like disk defrag, disk cleanup, etc that are safer than these other programs.

Optimize Windows 7

Most tech enthusiasts won't run the corrupt factory preinstalled Windows 7 with all of the bloatware and duplicate utilties which throttle Windows 7 from its native performance.

Instead you should Clean Reinstall - Factory OEM Windows 7 following the steps to get a perfect install.