A routine January Patch Tuesday rollup (KB5074109) accidentally left parts of Microsoft’s classic Outlook experience unstable for a measurable number of users, triggering freezes, lingering OUTLOOK.EXE processes, lost Sent Items and a rapid sequence of follow‑up fixes and mitigations from...
boot failure
bootfailures
cloud file i o
emergency updates
january 2026
january 2026 updates
kb5074109
kb5078127
known issue rollback
onedrive
onedrive pst
out of band updates
outlook
outlook classic
outlook pop
outlook pst hangs
patch tuesday
rollback
unmountable boot volume
update regression
windows11windows11bootfailureswindows11boot issues
windows11 issues
windows11 update
windows11 updates
windows updates
winre recovery