How to FIX: CBS.LOG Causes High Disk Activity and Fills the Hard Drive.
Step 1. Stop the Windows Module Installer Service.
The CBS.LOG file is managed by the ‘Windows Modules Installer’ (TrustedInstaller) service, so first proceed and stop the service. To do that:
1. Simultaneously press the Windows + R keys to open run command box.
2. In run command box, type: services.msc and press Enter.
3. Right click on Function Discovery Provider Host service and click Stop.
Step 2. Delete the CBS.LOG & the .CAB files.
1. Open Windows Explorer and navigate to ‘C:\Windows\Logs\CBS‘ folder.
2. Delete the CBS.log file.
3. Now navigate to ‘C:\Windows\Temp‘ folder.
4. Delete all the .cab files.
5. When done, restart your PC.
6. Proceed and install all the available updates.