I need to get value for "UninstallString" in
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall {1535CAA3-9F33-414E-8987-0365169BE741}
calling:
Get-Item -path HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\{1535CAA3-9F33-414E-8987-0365169BE741}
results in Get-Item : A positional parameter cannot be found that accepts argument '1535CAA3-9F33-414E-8987-0365169BE741'.
To complement js2010's helpful answer, which notes that lack of quoting is your primary problem ({ and } are PowerShell metacharacters):
In PowerShell v5 and above, you can use the Get-ItemPropertyValue cmdlet to directly return the data associated with a registry key's value:
# Note the use of '...' around the registry path
# and the value name UninstallString at the end.
Get-ItemPropertyValue 'HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\{1535CAA3-9F33-414E-8987-0365169BE741}' UninstallString
As for what you tried:
An unquoted argument such as HKLM:\...\{1535CAA3-9F33-414E-8987-0365169BE741} is processed as follows:
Because {...} creates a script block, it is considered the start of a separate argument, and string 'HKLM:\...\' and script block {1535CAA3-9F33-414E-8987-0365169BE741} are passed as two arguments.
Because Get-Item didn't expect an extra (positional) argument, it complained accordingly, and used the string representation of the script block in its error message.
{ and }, which you can verify with {1535CAA3-9F33-414E-8987-0365169BE741}.ToString()As noted, quoting is the solution, and since the path contains neither PowerShell variable references nor subexpressions, using a single-quoted, i.e. verbatim string literal ('...') is best.
The (usually less desirable) alternative is to stick with an unquoted argument and use individual escaping of PowerShell metacharacters with ` (the so-called backtick); e.g.:
Write-Output HKLM:\...\`{1535CAA3-9F33-414E-8987-0365169BE741`}
Something like this with quotes, since curly brackets look like a scriptblock to powershell:
get-itemproperty 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{013DB423-A8DE-4423-9E50-D45ED1041789}' uninstallstring |
% uninstallstring
MsiExec.exe /I{013DB423-A8DE-4423-9E50-D45ED1041789}
Although for an msi you can uninstall with this in powershell 5.1:
get-package *chrome* | uninstall-package
For other non-msi installs the uninstallstring is here. Usually you have to add an extra option like "/S" for silent uninstall.
get-package *firefox* | % { $_.metadata['uninstallstring'] }
"C:\Program Files\Mozilla Firefox\uninstall\helper.exe"
As I commented you need to wrap the path in "" however that still won't work. To get a registry value in powershell use Registry::HKEY_LOCAL_MACHINE\... as the path. And once you get the RegistryKey object you can use GetValue(string name) to get the value of UninstallString. So your command would look something like this:
(Get-Item -path "Registry::HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\{1535CAA3-9F33-414E-8987-0365169BE741}").GetValue("UninstallString")
HKLM: path work just fine in PowerShell: there are two registry "drives" predefined in PowerShell HKLM: (HKEY_LOCAL_MACHINE) and HKCU: (HKEY_CURRENT_USER) - run Get-PSDrive -PSProvider Registry to verify.Get-ItemPropertyValue: Get-ItemPropertyValue 'HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\{1535CAA3-9F33-414E-8987-0365169BE741}' UninstallString
"". But even if you do that I don't think you can access the registry value like that.