PossumMC

Internal storage A full range of hard disk and solid state storage drives, including some with self-encrypting capabilities, in capacities to meet today’s requirements. HP Compaq Elite 8300 PC Product Specifications | HP® Customer Support
Based on my check, it seems that they indeed provide both HDDs and SSDs in HP Compaq Elite 8300 PCs, which suggests that you can replace the existing HDD. Moreover, it should be relatively straightforward to clone the contents of the HDD onto the new SSD without reinstalling your Windows operating system.

I Agree with NIM.
Using Windows 10 LTSC would also help, because it is much less bloated. You could probably achieve something similar with some debloating scripts/applications in Windows 10 consumer edition; I've stumbled upon this yesterday: https://forums.mydigitallife.net/threads/slimdown10-–-turn-windows-10-22h2-into-classic-legacy-windows.86552/

As a Windows 11 user having the default setup, I believe that the greatest benefit can be attained by transitioning from an HDD to either an SSD or an NVMe drive. This switch leads to a notable enhancement in speed, irrespective of the other components in the configuration.

Welcome to Wincert fatal-destiny