Can't Set New-ItemProperty to Registry Path Containing Astrix

PowerShell Help
1

While converting a few .reg files to .ps1, I’ve run into a problem with this script:

$key = "Registry::HKEY_CLASSES_ROOT\*\shell\Open with Notepad"
New-Item -Path $key"\Command" -Value "Notepad.exe `"%1`"" -Force
New-ItemProperty -Path $key -Name "Icon" -Value "Notepad.exe" -PropertyType String -Force

While New-Item creates the key just fine, New-ItemProperty is getting hung up on the astrix in the path, interpreting it as a wildcard. Is there any way around this?

2

Use single quotes instead of double quotes around your key string. Single quotes indicate a string literal.

$key = 'Registry::HKEY_CLASSES_ROOT\*\shell\Open with Notepad'
New-Item -Path $key"\Command" -Value "Notepad.exe `"%1`"" -Force
New-ItemProperty -Path $key -Name "Icon" -Value "Notepad.exe" -PropertyType String -Force

Alternately, if you want to use double quotes, you can use a back tick to tell powershell not to interpret the special meaning of *

$key = "Registry::HKEY_CLASSES_ROOT\`*\shell\Open with Notepad"
New-Item -Path $key"\Command" -Value "Notepad.exe `"%1`"" -Force
New-ItemProperty -Path $key -Name "Icon" -Value "Notepad.exe" -PropertyType String -Force
3

That’s not the first time I’ve seen PowerShell’s path abstractions have problems with the realities of the registry. (It also has trouble with paths that contain forward slashes in a key name.)

You can work around this by using the underlying .NET methods instead:

$hive = [Microsoft.Win32.RegistryKey]::OpenBaseKey('ClassesRoot', 'Default')
$subKey = $hive.CreateSubKey('*\shell\Open with Notepad', $true)
$subkey.SetValue('Icon', 'Notepad.exe', 'String')
$subKey = $subKey.CreateSubKey('Command', $true)
$subkey.SetValue($null, "Notepad.exe `"%1`"", 'String')

I’m not 100% sure if I’ve translated your code properly, but you can run this and then verify the proper keys / values with regedit.

4

Thanks, for the tip about the single quotes, Curtis. I wasn’t aware they’re treated differently. Unfortunately neither option worked in this case.

Your code worked perfectly, Dave. Thanks! I guess these cmdlets never expected to have to deal with these otherwise illegal characters.

5

I tested with the escape character and it worked for me. Granted, the New-ItemProperty took a while, but it completed.

$key = "Registry::HKEY_CLASSES_ROOT\`*\shell\Open with Notepad"
New-Item -Path $key"\Command" -Value "Notepad.exe `"%1`"" -Force
New-ItemProperty -Path $key -Name "Icon" -Value "Notepad.exe" -PropertyType String