For Users with CA Antivirus installed on their machine - this post will be a big sigh of relief.

SVCHOST.exe and CA Antivirus software have been lately fighting with each other for CPU and memory resources. CA has confirmed this problem and will return with a fix soon.

Till then temporary solution to your slow computer and SVCHOST hogging 50% of your CPU is:

Disable CA Antivirus Realtime protection

OR

Disable Automatic Updates

OR

Exclude CA Antivirus to scan *.msi and *.msp files.

The above will definitely solve your SVCHOST.exe and Automatic updates problem