ArcInstaller

Install, remove, and repair the ARC icon theme on Windows 10 and 11.

Screenshots

All four captures come from the shipped dist\ArcInstaller.exe.

The main window as the shipped exe opens it.

All five theme variants in the picker.

The More ▾ overflow menu: Remove theme…, Repair…, and Open logs folder.

The details log strip showing a run's log.

Install

Download ArcInstaller.exe from the latest release, or build the one-file installer from source (that path needs network access at fetch time):

git clone https://github.com/nathwn12/arc-installer.git
cd arc-installer
pwsh -NoProfile -File .\fetch-theme.ps1
powershell -NoProfile -ExecutionPolicy Bypass -File .\build.ps1

fetch-theme.ps1 downloads the four upstream packs, verifies every archive against a pinned SHA-256, and derives Arc Dark Grey locally. build.ps1 stages the payload and compiles dist\ArcInstaller.exe.

Install the theme in one command. The exe requires Administrator, so Windows asks once at launch:

.\dist\ArcInstaller.exe --cli -Action install -Variant dark-grey -Yes

That single command checks the variant source, captures the pristine payloads if this is a fresh machine, merges the chosen variant, installs it, refreshes every logged-on profile's icon and thumbnail cache, and verifies the result. To change variant later, run the same command with another id from the table below; the switch re-merges, restores, and reinstalls in one action.

Or use the window

Run dist\ArcInstaller.exe without --cli. The window has three actions:

• Install theme (primary): installs the selected variant. The dropdown preselects what is installed, and a variant switch confirms once before anything is written.
• Check status: read-only. Shows the installed variant, timestamp, payload hashes, and verification result; changes nothing.
• More ▾: Remove theme… puts the stock Windows payloads back, Repair… re-applies only when the live files match what this tool recorded and never overwrites an unknown payload, and Open logs folder opens %ProgramData%\ArcIcons\logs.

Details ▸ expands the log strip. A failure turns the status line red, shows the first error in a red bar, and opens the details automatically, so a refusal is never silent or mistaken for success.

Remove the theme

One command puts the stock Windows payloads back, refreshes every logged-on profile, and verifies the original state:

.\dist\ArcInstaller.exe --cli -Action uninstall -Yes

Uninstall keeps originals\ (the only pristine copy) and logs\ so a reinstall stays safe. Add -CleanState to also remove state.json, installed-manifest.json, and stage\:

.\dist\ArcInstaller.exe --cli -Action uninstall -CleanState -Yes

The exe is portable and keeps its working files under %ProgramData%\ArcIcons. After uninstall passes verification, remove that folder to delete the tooling, the pristine backup, and the logs:

Remove-Item -Recurse -Force "$env:ProgramData\ArcIcons"

Keep the folder if you may want to install again without rebuilding; the pristine backup is what uninstall restores.

Variants

-Variant	Name	Source
arc	ARC	niivu's upstream ARC pack
arc-symbolic	ARC Symbolic	niivu's upstream symbolic pack
neutral-brown	Arc Neutral Brown	niivu's upstream pack
neutral-grey	Arc Neutral Grey	niivu's upstream pack
dark-grey	Arc Dark Grey	derived locally from Arc Neutral Grey

dark-grey is the tool default and a complete variant: all three payloads are recolored, one factor per icon group, with a group luminance floor of 64. The derivation and measured hashes are in docs/arc-dark-grey-variant.md.

Command line

--cli runs the installed controller instead of opening the window. Without --cli the exe launches the window. Normal use is three commands: install, remove, and check status.

.\dist\ArcInstaller.exe --cli -Action install -Variant dark-grey -Yes
.\dist\ArcInstaller.exe --cli -Action uninstall -Yes
.\dist\ArcInstaller.exe --cli -Action status

Option	Effect
-Action	install, uninstall, or status for normal use; every verb is listed below
-Variant	Variant id or display name; default dark-grey
-Yes	Skip confirmations
-DryRun	Preview an install, uninstall, or repair without writing
-CleanState	With uninstall: also remove state and stage files; keeps originals\ and logs\

Advanced commands

These are the CLI-only verbs. install, uninstall, and status are the normal path shown above; the rest are for recovery and diagnostics, not normal use. Each is documented in the repair manual.

Action	What it does
install	Full install: source check, capture if fresh, merge and restore if switching, apply, per-user refresh, verify
uninstall	Full removal: restore the pristine originals, per-user refresh, verify original state
status	Same read-only check as Check status; prints hashes and exits non-zero on FAIL
repair	Re-apply only when the live payload matches the recorded original; never overwrites an unknown payload
refresh	Rebuild the shell icon cache for every logged-on profile
merge	Rebuild the staged payload from the originals and the theme
apply	Write the recorded merge to the live payloads without the controller
revert	Restore the pristine originals without the full uninstall orchestration
task-on	Enable auto-repair at startup
task-off	Disable auto-repair at startup

Every verb runs through the same exe, for example:

.\dist\ArcInstaller.exe --cli -Action status
.\dist\ArcInstaller.exe --cli -Action repair -DryRun

A first install cannot be previewed: it must capture the pristine payloads and merge, so -DryRun reports that and changes nothing.

Requirements

• Windows 10 or 11, x64.
• Administrator rights. The exe manifest requires elevation; the scripts ask for it when run directly.
• Windows PowerShell 5.1, built into Windows, runs the installed scripts.
• PowerShell 7 for the fetch step shown above.
• The .NET Framework 4 C# compiler that ships with Windows, for the build.
• No network access after the build; the theme shapes are embedded in the exe.

Recovery

1. Remove the theme first while the live payloads are still the ones this tool installed: .\dist\ArcInstaller.exe --cli -Action uninstall -Yes.
2. Check the result: .\dist\ArcInstaller.exe --cli -Action status prints PASS or FAIL with per-check detail.
3. If a Windows Update replaced the payloads, Repair deliberately writes nothing to the new files. The repair manual's re-merge procedure rebases the new originals, rebuilds, and applies.
4. If removal and status still fail, use the OS backstop: sfc /scannow, then DISM /Online /Cleanup-Image /RestoreHealth.

The full ladder and the measured file-replacement mechanism are in docs/REPAIR-MANUAL.md.

Troubleshooting

• Icons look unchanged after install. Install and remove rebuild every logged-on profile's icon and thumbnail cache, then restart that profile's Explorer. A profile that is not signed in is not touched: sign that user in and run -Action refresh, or sign out and back in.
• Status is FAIL after install. Read the FAIL lines, then remove the theme. Every exit path restores and verifies the shell, so Explorer is not left stopped.
• variant source ... is missing. The chosen variant's payload is absent from the extracted theme tree; rebuild with fetch-theme.ps1, then run the new exe.
• needs Administrator. Accept the UAC prompt, or start from an elevated terminal.
• sfc /scannow flags a SystemResources file. That is expected after a resource edit; remove the theme before running a repair install.
• Explorer is not running. The scripts restore it before exit; if it is still absent, start it with Start-Process explorer.

Install layout and file roles: docs/WHERE-IT-LIVES.md.

Known limitations

• Windows 10 needs all three payloads. Install replaces imageres.dll.mun, imagesp1.dll.mun and zipfldr.dll.mun. A Windows 10 build that does not ship imagesp1.dll.mun cannot install: capture stops with imagesp1.dll.mun not found. Windows 11 x64 English is the tested target; every other build is unverified.
• English theme resources only. The bundled packs carry English (language 1033) resources, and a theme icon missing from the stock payload is added as 1033 only. A non-English Windows may keep some stock glyphs.
• A hard crash or power loss mid-apply can leave the SystemResources directory ACL granted to Administrators and a payload missing. %ProgramData%\ArcIcons\logs\apply.journal.jsonl names the last operation in flight. -Action repair does not fix this: a missing or unknown live file is drift-unknown-payload, so it writes nothing. Recovery is uninstall, then reinstall: .\dist\ArcInstaller.exe --cli -Action uninstall -Yes, then .\dist\ArcInstaller.exe --cli -Action install -Variant <id> -Yes. restore.ps1 recreates the missing payload and restores the directory baseline.
• A Windows Update that replaces a payload blocks a reinstall until a rebase or re-merge. -Action install and the window's Install theme both refuse with live payload is neither the recorded original nor the recorded merge, and -Action repair reports drift-unknown-payload without writing. Do not use -Action revert or -Action uninstall before that rebase: both go straight through restore.ps1, which puts the pre-update originals back and rolls the update back.
• Uninstall leaves traces. Restored payloads are new files copied from originals\, not the original WinSxS hardlinks, so the original file identity is not restored even when bytes and SDDL match. One directory control flag (D:PAI) cannot be reproduced byte-for-byte; the restore journals it as exact=false. -Action uninstall also does not remove the ArcIcons-Repair scheduled task (when auto-repair was enabled) or %ProgramData%\ArcIcons: run install-autorepair.ps1 -Uninstall and delete the folder by hand.
• Multi-user refresh is proven by transport, not by two live profiles. tests\Test-UserRefreshTransport.ps1 proves the per-profile InteractiveToken transport and the worker's SID/session receipt with -DryRun; the actual cache drop in a second logged-on profile is not covered by a live test here.
• No ARM64 build. The installer and payload target x64 Windows only.

Development

powershell -NoProfile -ExecutionPolicy Bypass -File .\build.ps1
.\dist\ArcInstaller.exe --selftest
powershell -NoProfile -File .\verify.ps1
powershell -NoProfile -File .\tests\Test-VariantParity.ps1

--selftest unpacks the embedded payload and checks every extracted file against the embedded manifest; exit 0 means the payload is intact. It needs an elevated shell. verify.ps1 is a read-only host check and needs the tool root with its recorded originals. Test-VariantParity.ps1 pins the three variant tables to the same five ids.

License

MIT. See LICENSE.

Links

• Repair manual
• Install map
• Arc Dark Grey derivation
• MIT

_{Built by nathwn12 · All projects}