Upgrading PowerShell 7 Without Killing Your Claude Code Session

Written as a private engineering note, 23 June 2026, after upgrading PowerShell 7.6.2 to 7.6.3 on Windows. Republished here, lightly edited for a reader.

The problem#

Upgrading PowerShell 7 from inside a Claude Code session repeatedly killed the session. The terminal was left showing only:

Resume this session with:
claude --resume <id>

Why it happens#

Claude Code runs inside a pwsh.exe (PowerShell 7) terminal window. The PowerShell MSI replaces C:\Program Files\PowerShell\7\pwsh.exe. Windows Installer's Restart Manager detects every process holding that file — including the host terminal — and force-closes it. The act of installing closes the very terminal Claude is running in.

The key insight, and the thing that wasted the most time: opening a different terminal to launch the installer does not help. Restart Manager targets the process that holds the file, which is the host terminal — not the process that launched msiexec.

Two extra gotchas#

winget lags behind. It only knew about 7.6.2 when 7.6.3 was already out. Get the MSI straight from GitHub instead:

• Latest tag: https://api.github.com/repos/PowerShell/PowerShell/releases/latest
• MSI: https://github.com/PowerShell/PowerShell/releases/download/v<VER>/PowerShell-<VER>-win-x64.msi

It needs admin. This is a per-machine install into Program Files, and the session normally runs non-elevated, so expect a UAC prompt.

The fix — never run the installer from inside the session#

Three options, in order of preference.

Option B — cleanest, and the one that worked#

1. Download the MSI.
2. Write a self-elevating .cmd that runs msiexec /i "<msi>" /passive /norestart.
3. Then:
   • Exit Claude and fully close the host PowerShell window. Exiting Claude alone leaves the pwsh window still holding the binary.
   • Double-click the .cmd. It runs in cmd, not pwsh. Answer Yes to UAC.
4. It installs immediately and completely — no reboot needed. Reopen Claude afterwards.

The .cmd should check tasklist for pwsh.exe and pause with a warning if any PowerShell 7 process is still running.

Reference install-pwsh.cmd#

@echo off
setlocal
set "MSI=<path to>\PowerShell-7.6.3-win-x64.msi"
set "LOG=<path to>\install.log"
 
REM --- Self-elevate (UAC) if not already admin ---
net session >nul 2>&1
if %errorlevel% neq 0 (
  echo Requesting administrator privileges...
  powershell -NoProfile -Command "Start-Process -FilePath '%~f0' -Verb RunAs"
  exit /b
)
 
REM --- Warn if any pwsh.exe still running ---
tasklist /fi "imagename eq pwsh.exe" 2>nul | find /i "pwsh.exe" >nul
if %errorlevel%==0 (
  echo [WARNING] pwsh.exe still running. Close ALL PowerShell 7 windows, then press any key.
  pause >nul
)
 
msiexec /i "%MSI%" /passive /norestart /l*v "%LOG%"
echo Exit code: %errorlevel%
"C:\Program Files\PowerShell\7\pwsh.exe" -NoProfile -Command "$PSVersionTable.PSVersion.ToString()"
pause

Option A — install now, finalize on reboot#

Launch elevated msiexec with Restart Manager disabled:

msiexec /i "<msi>" /qn /norestart MSIRESTARTMANAGERCONTROL=Disable REBOOT=ReallySuppress

With Restart Manager disabled, the in-use pwsh.exe is queued via PendingFileRenameOperations and swapped on the next reboot; the current session survives. Costs one UAC click plus a later reboot.

Option C — scheduled task#

Register a one-time scheduled task with highest privileges to run the MSI at next logon, then self-delete. You get a clean install at logon, when no pwsh holds the binary. Costs one UAC to register plus a re-logon or reboot.

Verify success#

This works even while the old host is still live, because it checks the on-disk binary rather than the running process:

& "C:\Program Files\PowerShell\7\pwsh.exe" -NoProfile -Command '$PSVersionTable.PSVersion.ToString()'
(Get-Item "C:\Program Files\PowerShell\7\pwsh.exe").VersionInfo.ProductVersion

Notes#

• Put the MSI, the .cmd and the log in a scratch directory, and clean it up afterwards.
• Confirmed working on 2026-06-23: upgraded 7.6.2 → 7.6.3 via Option B.