If you are satisifed that the computer is running OK otherwise, try disabling System Restore, reboot the computer, then run Disk Cleanup. Afterwards, re-enable System Restore.
the System Volume Information folder is a hidden folder that stores System Restore backup files, and the catalog.wci folder is a sub-folder of the System Volume Information folder.
By disabling System Restore, you may delete these sub-folders and if so they will be re-created again when you re-enable System Restore.
I wouldn't consider deleting the catalog.wci folder and contents manually, but see if disabling System Restore does it for you.
Computer freezes and found a related Error in ''Events showing each time the computer freezes''
Any suggestions on how to rectify to do the ''Cleanup''?
Event Type: Error
Event Source: Ci
Event Category: CI Service
Event ID: 4126
Time: 10:50:41 PM
Cleaning up corrupt content index metadata on c:\system volume information\catalog.wci. Index will be automatically restored by refiltering all documents.