Configuration

Settings
Pause
Schedule
Reboot detection
On-disk locations

WUM stores configuration in the Windows registry (the same locations Windows itself uses) and writes rolling logs on disk. This page documents the exact keys and values each command writes, so you know precisely what changes on your system.

All registry access is through RegistryHelper, which opens the 64-bit view of HKEY_LOCAL_MACHINE (HKLM). Writing therefore requires Administrator.

Settings

wum settings reads/writes via SettingsService → UpdateService.GetSettingsAsync/SaveSettingsAsync.

Registry paths

Constant	Path (under `HKLM`)
UX settings	`SOFTWARE\Microsoft\WindowsUpdate\UX\Settings`
AU policy	`SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU`

Keys (`wum settings set <key> <value>`)

Key	Value range	Maps to	Default
`auto-download`	`true`/`false`	`AUOptions ≥ 3`	`true`
`auto-install`	`true`/`false`	`AUOptions == 4`	`false`
`install-drivers`	`true`/`false`	`InstallDrivers`	`true`
`install-optional`	`true`/`false`	`InstallOptional`	`false`
`notify-new`	`true`/`false`	`NotifyOnNewUpdates`	`true`
`notify-complete`	`true`/`false`	`NotifyOnInstallComplete`	`true`
`pause-metered`	`true`/`false`	`AllowAutoWindowsUpdateDownloadOverMeteredNetwork == 0`	`true`
`defer-feature`	`0`–`365`	`DeferFeatureUpdatesDays`	`0`
`defer-quality`	`0`–`30`	`DeferQualityUpdatesDays`	`0`
`active-hours`	`start-end` (e.g. `8-22`)	`ActiveHoursStart` / `ActiveHoursEnd`	`8`–`22`

Boolean parsing: true, 1, yes, on → true; anything else → false (SettingsService.ParseBool).

active-hours expects two integers separated by -. wum settings set active-hours 9-18 sets start=9, end=18.

Note on persistence: SaveSettingsAsync currently persists Active Hours (ActiveHoursStart/ActiveHoursEnd) to the UX settings key. The displayed values for auto-download/install etc. are read back from the AU policy + UX keys on GetSettingsAsync. wum settings reset writes a fresh default UpdateSettings.

Examples

wum settings                              # Show all current values
wum settings set auto-download true
wum settings set active-hours 9-18
wum settings set defer-feature 30
wum settings reset                        # Confirm, then restore defaults

Pause

wum pause / wum pause resume via PauseService.

Path: HKLM\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings

On pause (--days N, clamped 1–35), these string values are written (UTC, yyyy-MM-ddTHH:mm:ssZ):

Value name	Meaning
`PauseFeatureUpdatesStartTime`	now (UTC)
`PauseFeatureUpdatesEndTime`	now + N days
`PauseQualityUpdatesStartTime`	now (UTC)
`PauseQualityUpdatesEndTime`	now + N days
`PauseUpdatesExpiryTime`	now + N days

On resume all five values are deleted.

Reading state (GetPauseInfoAsync, used by wum status): IsPaused = now < PauseUpdatesExpiryTime; PausedUntil and PausedOn are converted to local time; DaysLeft is derived.

wum pause --days 14            # Sets the five values, expiry = now + 14d
wum pause resume               # Deletes them
wum status                     # Shows "Updates Paused: Yes - until … (Nd left)"

Schedule

wum schedule via SchedulerService (registry-persisted). The model:

class UpdateSchedule {
    bool      Enabled;            // false
    DayOfWeek Day;               // Sunday
    TimeSpan  Time;              // 02:00
    bool      AutoInstall;       // false
    bool      AutoReboot;        // false
    bool      InstallAll;        // false (else security only)
}

set validates --day against DayOfWeek and --time against HH:mm, then saves.
NextRun() computes the next occurrence of Day at Time (rolls to next week if today’s slot already passed).
IsWithinSchedule(now) is true within a 2-hour window from Time on the matching day.

wum schedule set --day Friday --time 03:00 --auto-install --auto-reboot --all
wum schedule show              # Day/Time/Auto Install/Auto Reboot/Install All/Next Run
wum schedule clear

Reboot detection

IsRebootRequired() first asks Microsoft.Update.SystemInfo.RebootRequired, then falls back to update-specific registry markers. PendingFileRenameOperations is deliberately excluded (noisy, set by routine installers):

Registry key (presence = reboot)
`HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\RebootRequired`
`HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\RebootPending`

diagnose additionally reports …\RebootRequired\UpdateExeVolatile as an UpdateExe reason. Used by wum status, wum reboot, and wum install’s post-install prompt.

wum reboot serializes commit/restart operations with a machine-wide mutex and writes HKLM\SOFTWARE\WUM\Runtime\UpdateCommitBootSession. The value records Started|<boot> before the non-repeatable WUA call and Committed|<boot> after success. It is not scan data and is ignored after restart. A retry after cancellation or interruption schedules the required reboot without risking a second unsupported Commit(0).

On-disk locations

Path	Written by	Notes
`%ProgramData%\WUM\logs\wum-YYYY-MM-DD.log`	Serilog	Elevated-session daily roll, 7-day retention
`%LocalAppData%\WUM\logs\wum-YYYY-MM-DD.log`	Serilog	Standard-user daily roll, 7-day retention

%ProgramData% resolves via Environment.SpecialFolder.CommonApplicationData (normally C:\ProgramData). Standard-user commands use %LocalAppData%, avoiding permission conflicts with logs created by elevated operations.

Available-update results are not written to disk; each scan queries current WUA state.

Next: Diagnostics →