windows3-9  Exercise 2: What Changed Before the Crashes
=================================================================

Verification: Level 1 (run on the author's machine, read-only, no administrator rights).

Prediction (work this out before running the script):

  Before running: what do you expect to have changed just before your first unexpected restart?

Command (change_timeline.ps1 saved in the current folder; the optional parameter -Days sets how far back it looks, default 120):

  .\change_timeline.ps1

Output (real, from the author's machine on 2026-10-24; your numbers will differ):

  2026-07-15 16:24  CHANGE   2026-07 .NET Framework Security Update (KB5100998)
  2026-07-16 08:38  CHANGE   Windows Malicious Software Removal Tool x64 - v5.143 (KB890830)
  2026-07-16 17:21  CHANGE   2026-07 .NET Framework Security Update (KB5100998)
  2026-07-21 02:24  CHANGE   2026-07 Update (KB5121767) (26200.8894)
  2026-07-23 09:34  CHANGE   Microsoft Corporation AudioProcessingObject Driver Update (1.0.4.7057)
  2026-07-24 21:33  RESTART  unexpected, stop code 0x0
  2026-07-30 03:57  CHANGE   2026-07 Preview Update (KB5101684) (26200.8973)
  2026-08-01 06:26  CHANGE   Update for Windows Security platform - KB5007651 (Version 10.0.29628.1000)
  2026-08-13 01:51  CHANGE   2026-08 .NET Framework Security Update (KB5120708)
  2026-08-13 02:10  CHANGE   2026-08 Security Update (KB5121003) (26200.9168)
  2026-08-13 02:16  CHANGE   Windows Malicious Software Removal Tool x64 - v5.144 (KB890830)
  2026-08-29 04:34  CHANGE   2026-08 .NET Framework Preview Update (KB5122385)
  2026-08-29 04:53  CHANGE   2026-08 Preview Update (KB5120998) (26200.9278)
  2026-09-09 20:52  CHANGE   2026-09 .NET Framework Security Update (KB5126052)
  2026-09-09 21:10  CHANGE   2026-09 Security Update (KB5124008) (26200.9445)
  2026-09-09 21:17  CHANGE   Windows Malicious Software Removal Tool x64 - v5.145 (KB890830)
  2026-09-15 19:39  CHANGE   2026-09 Security Update (KB5129195) (26200.9457)
  2026-09-22 20:40  CHANGE   2026-09 Preview Update (KB5124010) (26200.9550)
  2026-10-08 10:33  CHANGE   Windows 11, version 26H2
  2026-10-08 17:57  CHANGE   Windows 11, version 26H2
  2026-10-14 01:14  CHANGE   Windows Malicious Software Removal Tool x64 - v5.146 (KB890830)
  2026-10-14 01:22  CHANGE   2026-10 .NET Framework Security Update (KB5127694)
  2026-10-14 03:11  CHANGE   2026-10 Security Update (KB5127648) (26300.9711)
  2026-10-14 08:11  CHANGE   2026-10 .NET Framework Security Update (KB5127694)
  2026-10-19 15:38  RESTART  unexpected, stop code 0x13A
  2026-10-23 19:10  RESTART  unexpected, stop code 0x0
  2026-10-24 17:02  RESTART  unexpected, stop code 0x13A

WHY THIS WORKS AS AN ANSWER
---------------------------
  Supported: this PC had no unexpected restart between 24 July and 19 October (87 days), then three in six days;
  the feature update to Windows 11 version 26H2 was installed on 8 October and the October security update on the
  14th, so the crashes began after the biggest change in the list.
  Not shown: which component of the update (if any) is responsible; that the update itself is the cause rather than
  something else that changed in the same window (Store app updates and the Defender definitions were filtered out
  of this list); anything about drivers installed by other means than Windows Update.
  Common mistakes: treating the closest change as the cause; forgetting that a rare crash needs a long quiet period
  before you can say a change fixed it; and ignoring the 23 October restart, which has no stop code and may not be
  the same problem.