KB5077181 was released about a month ago as part of the February Patch Tuesday rollout. When the update first arrived, users reported a wide range of problems, including boot loops, login errors, and installation issues.
Microsoft has now acknowledged another problem linked to the same update. Some affected users see the message “C:\ is not accessible – Access denied” when trying to open the system drive.


There was a story going around back in September ago about the person whose wife used OneDrive on her phone. It had taken upon itself to copy 25+GB of data on the phone into OneDrive, despite only having the free account tier, and copying it to their Windows 11 PC. There it completely filled up its small SSD boot drive, putting it into a condition of extremely low disk space, which in made it impossible for Windows to boot. Here it is.
I doubt that story. I’m a linux user at home but at work I admin windows and linux systems. I can see his logic because hes thinking how I would. But windows doesnt behave like that. On linux you can fill a drive and get issues booting but windows leaves space so that even when the user drive is full the system can still create temp files needed for operation. Whatever he did trying to get around the default behavior he misconfigured something