Sure, apologies - I was on W11 23H2 and had problems upgrading to W11 24H2. The problem below is the one I'm describing.
I downloaded the free tool numerous people recommended and it showed that my reserved space was @ 93% full. Whereas using the diskmgmnt.msc, it showed 100% free....go figure. I followed the Cmd instructions on how to clear the fonts from the reserved fonts dir and it freed-up about 25%. I rebooted and tried again, it took about an hour for the full process to run and restart. (HP Z Book with i7 processor). However, my Surface Pro and MSI Cubi 5 devices were also running W11 23H2 upgraded without issues.
Yes, I'm talking about the standard windows desktop and the latest M365 Outlook.
Following the upgrade to 24H2, it forced me to start the new Outlook so I checked the .pst issue and found out it had been resolved per my update.
Cheers
MC