Issue with updating Dell optiplex 3030 running Win11

Hi, 

I'm hoping someone can help, I'm a bit out of touch with Windows (my personal laptop is Apple), but I have to run a software for work that requires Windows so I've purchased a Dell Optiplex 3030 AIO second hand (came with a factory reset and running Win11). 

However, I'm having a few issues. It's slow, like super slow for all things. It's 8GB RAM, 3.00GHZ processor with 500GB HDD with 387 GB free. I think the issue is stemming from the fact that it really doesn't want to update. 

I started up and ran a check or updates and let it do it's thing. Also opened Dell website and downloaded/installed updates for various drivers that recommended. Some of them installed, some came up error code and stopped short of installing. 

Currently its labouring over installing this - 2024-11 Cumulative Update Preview for Windows 11 Version 24H2 for x64-based Systems (KB5046740). But it seems to be stalled and every time I try it will say it's failed, retry then ponder for a while on a percentage before stopping again. 

Photoshop is saying my graphics drivers are currently 76 weeks since last update, but again it won't let me install any updates manually or automatically at this point. 

I'm also coming up against the Dell website telling me there's no Win11 support for this device but it's come with Win11 so not sure what to do there. 

We use a Dell touch screen AIO (not sure model) in work in the office and it's speedy as anything so I'm thinking is more of software issue than the desktop itself, but as I say I'm a bit out of practice with Windows and I'm at a loss as to how to at least get it running up to date so I can see if it helps speed and performance. 

So, can anyone help with my updating issue? 

Thanks!