Dell optiplex

See here: System Specs - Fill in at Ten Forums

Fill out as much as you can, especially the Manufacture and full model number of the computer if purchased or the system board if custom built, RAM, hard drives, etc.

Post a screen capture of a full screen Disk Management window with all fields expanded so we can see everything:

See this tutorial: Disk Management - How to Post a Screenshot of

Make sure you expand the fields as shown so all data can be seen.

Was Windows 10 an upgrade from Windows 7 or a previous Windows 10? You have two Recovery partitions, 480MB and 490MB.

Do you do image backups of your drive? If not, the best way to do this is to use Macrium Reflect Free to make an image backup to an external hard drive. If you don't have an external hard drive now is a good time to get one as regular backup should be a part of your normal process. You can get a 1TB external hard drive for $50 (less if on sale).

Please fill out your System Specs under My Computer. See here: System Specs - Fill in at Ten Forums
Fill out as much as you can, especially the Manufacture and full model number of the computer if purchased or the system board if custom built, CPU specs (speed, #cores), GPU info, RAM info, Hard drive info). See mine for an example.

Additionally, how much free space is available on the hard drive?

Has the computer always run slow or is this a recent development?