Hi,
The issue that you are facing is with SkyDrive Sync, I would suggest you to try turning off the sync option in SkyDrive and check if the CPU usage reduced after that.
Method 1:
Follow the steps to choose which settings to sync:
a. Swipe in from the right edge of the screen, tap Settings, and then tap Change PC settings.
(If you're using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, click Settings, and then click Change PC settings.)
b. Tap or click Sync your settings.
c. Under Settings to sync, turn off the settings you no longer want to sync.
Method 2:
If the issue persists, I suggest you to place the computer in a clean boot and check if it helps.
You may follow the article mentioned to perform a clean boot.
Perform a Clean Boot
Follow the instructions (Step 1 for Windows 8) given in this link to perform a clean boot:
http://support.microsoft.com/kb/929135
Note: After performing the troubleshooting steps in clean boot, follow these steps to return the computer to Normal startup mode.
a) Press the ‘Windows + R’ key on the keyboard.
b) In the ‘Run’ windows type ’MSCONFIG’ and click ‘Ok’.
c) On the General tab, click the Normal Startup option, and then click ok.
d) When you are prompted to restart the computer, click Restart.
For further reference, you may refer to the following Microsoft Help article.
http://windows.microsoft.com/en-US/skydrive/skydrive-help#skydrive-help=tab1
Please reply with the status of the issue, so that we could help you better.