@startuml BSOD Decision Workflow
' Decision flowchart for BSOD triage and repair
' Source of truth — all scripts follow this flow
' Scripts: src/skill/bsod-diagnostics/bin/

title BSOD Decision Workflow

start

:User reports BSOD or system instability;

== 1. PREREQUISITES ==

:Run **storage-cleanup.ps1**
Free disk space (need 30GB+ for upgrade);
note right: Rule 3: free space BEFORE any repair

if (Free > 30GB?) then (yes)
else (no)
  :Clean temp, WU cache, rotate dumps
  Check Windows\Installer (PatchCleaner)
  DISM /StartComponentCleanup /ResetBase;
  if (Free > 30GB now?) then (yes)
  else (no)
    #pink:STOP — cannot safely proceed
    Move data to external drive;
    stop
  endif
endif

== 2. QUICK TRIAGE ==

fork
  :Run **bsod-triage.ps1**;
fork again
  :Run **norton-check.ps1**;
fork again
  :Run **driver-check.ps1**;
end fork

== 3. ANALYZE ==

:Count bugcheck codes and patterns;

if (Norton quarantined\nsystem files today?) then (yes)
  :Restore from Norton quarantine
  Add exclusions (**NortonExclusions**);
  stop
else (no)
endif

switch (Bugcheck pattern?)
case (0x10E, 0x116, 0x119\nGPU/VRAM codes)
  :GPU driver is primary suspect;
  -> GPU path;
case (0x50, 0x1A, 0x0A\nMemory codes)
  :RAM or driver suspect;
  -> Memory path;
case (0x139\nKernel security)
  :Code bug or memory corruption
  Run **windbg-analyze.ps1** (bg);
  -> WinDbg path;
case (0x14F, 0x9F\nPower codes)
  :Power management issue;
  -> Driver path;
case (Multiple different codes\n3+ distinct bugchecks)
  :Hardware likely (RAM/thermal)
  Also run **windbg-analyze.ps1** (bg);
  -> Hardware path;
case (dwm.exe crash\nCan't login)
  :Boot Safe Mode
  Run **gpu-safe-mode.ps1 -Action disable**;
  -> GPU path;
endswitch

== 4. FIX ATTEMPT ==

partition "GPU path" {
  :Roll back GPU driver
  (Device Manager or **driver-check.ps1**);
  if (Rollback available?) then (yes)
    :Roll back via devmgmt.msc;
  else (no)
    :DDU clean install in Safe Mode
    Download previous stable driver;
  endif
  :Reboot and monitor;
  if (Crashes stopped?) then (yes)
    #lightgreen:RESOLVED — driver was the cause;
    stop
  else (no)
  endif
}

partition "WinDbg path" {
  :Check **windbg-analyze.ps1** output;
  if (Faulting module\nis system file?) then (yes)
    note right
      e.g. Wof.sys, Ntfs.sys
      Check if file corrupt:
      compare SHA256 with ISO copy
    end note
    -> System repair;
  else (driver .sys)
    :Update/rollback that specific driver;
    if (Crashes stopped?) then (yes)
      #lightgreen:RESOLVED;
      stop
    else (no)
    endif
  endif
}

partition "Memory path" {
  -> Hardware path;
}

partition "Driver path" {
  :Check recently installed drivers
  (**driver-check.ps1** — sorted by date);
  :Rollback suspect driver;
  if (Crashes stopped?) then (yes)
    #lightgreen:RESOLVED;
    stop
  else (no)
  endif
}

== 5. SYSTEM REPAIR (vendor tools only) ==

label System repair

:Run **system-repair.ps1**
(DISM /RestoreHealth then sfc /scannow);
note right
  Monitor with **dism-monitor.ps1**
  Rule 2: vendor tools only
end note

if (DISM succeeded?) then (yes)
  :Run sfc /scannow;
  :Reboot and monitor;
  if (Crashes stopped?) then (yes)
    #lightgreen:RESOLVED;
    stop
  else (no)
  endif
else (no — 0x800f0915 or other failure)
  :Run **fod-fix.ps1** (diagnostic only)
  to understand what's blocking DISM;
  note right #pink
    Do NOT remove packages or manifests.
    Do NOT tamper with CBS/WinSxS.
    Rule 1 + Rule 2.
  end note
endif

== 6. IN-PLACE UPGRADE (correct escalation) ==

:Ensure ISO available
(**download-win11-iso.ps1** if needed)
ISO naming: Win11_{ver}_{date}.iso;

:Run **inplace-repair.ps1**
setup.exe from ISO — "Keep everything";
note right
  Monitor with **upgrade-monitor.ps1**
  ~30-60 min, 1-2 reboots
  Replaces ALL system files
  Fixes CBS component store
end note

:Wait for upgrade to complete;

if (Upgrade succeeded?) then (yes)
  :Verify: run **bsod-triage.ps1**
  Check Wof.sys version updated
  Check no new crashes;
  if (Crashes stopped?) then (yes)
    #lightgreen:RESOLVED — system repaired;
    stop
  else (no)
  endif
else (no)
  #pink:Upgrade failed — check
  C:\$WINDOWS.~BT\Sources\Panther\setuperr.log;
  stop
endif

== 7. HARDWARE TESTS ==

label Hardware path

:Run **mdsched.exe** (basic, reboot);

if (MemDiag found errors?) then (yes)
  #orange:RAM failure confirmed
  Replace faulty DIMM;
  stop
else (no / passed)
  :Run **MemTest86** from USB
  4+ passes overnight;
  if (MemTest86 found errors?) then (yes)
    #orange:RAM failure confirmed
    Replace faulty DIMM;
    stop
  else (no)
    :Monitor thermals with HWiNFO64
    GPU throttle ~83C, CPU ~100C;
    if (Overheating?) then (yes)
      #orange:Thermal issue
      Clean fans / repaste;
      stop
    else (no)
      #pink:Unknown root cause
      Collect dumps for vendor support
      Consider clean Windows install;
      stop
    endif
  endif
endif

== 8. BUG REPORT (system file bugs) ==

if (Root cause is\nMicrosoft system file?) then (yes)
  :Prepare feedback folder
  (nanoLong-slug-feedback/)
  FEEDBACK-SUMMARY.md, dumps, logs, scripts;

  :Copy non-.txt files to .txt suffix
  (.md -> .md.txt, .ps1 -> .ps1.txt, .puml -> .puml.txt);

  :File on **Microsoft Q&A**
  https://learn.microsoft.com/answers/questions/ask
  Upload attachments via Edit page (Playwright MCP);
  note right
    Accepted: .xml .pdf .txt .log .jpeg .jpg .png .gif
    Max 3MB per file
    .dmp not accepted — reference by path
    Use Edit page, NOT comments (comments lose file links)
  end note

  #lightblue:Bug report filed — track for Microsoft response;
  stop
else (no — third-party driver)
  :Report to driver vendor (NVIDIA, etc.);
  stop
endif

@enduml