At first, make sure you really have some problems with CPU load.
Go down to Taskbar, right click on it, run and look at your Task Manager.
If your CPU load is high, check if Microsoft Search Protocol Host and Microsoft Search Filter Host processes both at high level load. If they are – you have this issues too.
So how to fix this?
Here is a guide:
Click the Start button => go into Control Panel. Make sure that you are in Icon view, not Category.
Go to Indexing options.
The first thing you need to do is to modify what are the indexing will check at.
Remove all the check marks except OS (C:) drive and click OK.
Then go to Advanced indexing options and click Rebuild index button.
Now you will see this message:
Rebuilding the index might take a long time to complete. Some view and search results might be incomplete until rebuilding is finished.
What it does is at the top of the Indexing options window your indexing will go from whatever number it is to zero and it’s going to start building index again. Click Close.
Once you do that after a few seconds you need to look at your Task manager again and notice that Search Protocol Host and Search Filter Host processes are taking much lower CPU load now.