Here are some tips from Microsoft at this link that cover both Windows 10 and 11 for systems that are still using a hard drive. With that said, in my personal experience after some of these steps are performed, if the system is still slow (and using a standard hard drive), most likely upgrading to an SSD is going to be the best option to increase the performance of the system (especially as more OS updates are released).  
After hours of troubleshooting 100% disk usage on my Inspiron 15 5000 I narrowed it down to Dell software.  Unfortunately the prime suspect DCFWinService exists as a process but there is no such named service showing up in the service list.  I can stop the process but cannot disable the service.  So I removed all Dell programs through control panel and that cured the problem.  I would like you to tell me what if any risks or problems I may have after removing all the troublesome Dell (pardon me but it's true) - bloatware.   Thank you.
100% disk usage