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.
You don’t need
C:\. All your data should be in the 365 cloud anyway. Storing files locally inC:\leads to antipatterns like not paying Microsoft for 365 access (a.k.a “Software Piracy”)