WinMerge

Version documented: 2.16.38 Installer type: .exe (NSIS) Hives written: HKCU, HKLM, HKCR

📁 Registry Paths

Path	Hive	Purpose
`SOFTWARE\Thingamahoochie\WinMerge`	HKCU	User preferences
`SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WinMerge_is1`	HKLM	Uninstall entry
`HKCR\*\shell\WinMerge`	HKCR	"Compare with WinMerge" context menu
`HKCR\Directory\shell\WinMerge`	HKCR	Folder context menu integration

🔑 Keys

HKCU\SOFTWARE\Thingamahoochie\WinMerge

Value Name	Type	Example Data	Description
`WinLeft`	REG_DWORD	`100`	Main window left position
`WinTop`	REG_DWORD	`50`	Main window top position
`WinWidth`	REG_DWORD	`1200`	Main window width
`WinHeight`	REG_DWORD	`800`	Main window height
`TabSize`	REG_DWORD	`4`	Tab size for diff view
`Language`	REG_DWORD	`0`	UI language (0=system default)
`ShowUniqueLeft`	REG_DWORD	`1`	Show files unique to left
`ShowUniqueRight`	REG_DWORD	`1`	Show files unique to right
`ShowDifferent`	REG_DWORD	`1`	Show differing files
`ShowIdentical`	REG_DWORD	`0`	Show identical files
`LineFilterEnabled`	REG_DWORD	`0`	Enable line filter

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WinMerge_is1

Value Name	Type	Example Data	Description
`DisplayName`	REG_SZ	`WinMerge 2.16.38`	Display name
`DisplayVersion`	REG_SZ	`2.16.38`	Version
`Publisher`	REG_SZ	`Thingamahoochie Software`	Publisher
`InstallLocation`	REG_SZ	`C:\Program Files\WinMerge\`	Install path
`UninstallString`	REG_SZ	`"...\unins000.exe"`	Uninstaller

HKCR*\shell\WinMerge

Value Name	Type	Example Data	Description
`(Default)`	REG_SZ	`Compare with &WinMerge`	Context menu label
`command` (Default)	REG_SZ	`"WinMergeU.exe" "%1"`	Shell command

📝 Notes

WinMerge adds a "Compare with WinMerge" context menu entry for files and folders in Windows Explorer.
The HKCU\SOFTWARE\Thingamahoochie\WinMerge key stores all display and comparison preferences.
WinMerge can be used as a Git diff/merge tool by configuring git config --global merge.tool winmerge.

# Configure WinMerge as Git diff tool
git config --global diff.tool winmerge
git config --global difftool.winmerge.cmd '"C:\Program Files\WinMerge\WinMergeU.exe" -e -u "$LOCAL" "$REMOTE"'

# Export WinMerge preferences for migration
reg export "HKCU\SOFTWARE\Thingamahoochie\WinMerge" "$env:USERPROFILE\winmerge-settings.reg"

🗑️ Cleanup

# Remove WinMerge user preferences
Remove-Item -Path "HKCU:\SOFTWARE\Thingamahoochie\WinMerge" -Recurse -ErrorAction SilentlyContinue
Remove-Item -Path "HKCU:\SOFTWARE\Thingamahoochie" -Recurse -ErrorAction SilentlyContinue

# Remove Explorer context menu entries
Remove-Item -Path "HKCR:\*\shell\WinMerge" -Recurse -ErrorAction SilentlyContinue
Remove-Item -Path "HKCR:\Directory\shell\WinMerge" -Recurse -ErrorAction SilentlyContinue

📦 Package Managers

Manager	ID / Command
winget	`winget install Thingamahoochie.WinMerge`
Chocolatey	`choco install winmerge`
Scoop	`scoop install extras/winmerge`