Update registry key in Powershell

Question

Hi
I want to loop through a bunch of registry keys in powershell. In one of the keys there's a value I want to change.
I thought this would work and just return an error for all the keys where the values didn't exist
get-childitem
"hklm:\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}"
| foreach {set-itemproperty
-path $_
-name 'ChangeMe'
-value '22'}
However I'm getting this errors for all the keys even where the value exists.
set-itemproperty : Cannot find path 'C:\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}\0009' because it does not exist.
I've tinkered with Set-Location but it doesn't seem to make much difference. How can I transfer the path of the subkey to Set-itemProperty
Cheers
Alex

Answer 1

actually it is not mapped drive, it is more like registry object. 
for example:
set-location HKLM:\
get-childitem "hklm:\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}" | foreach {set-itemproperty -path $_ -name 'ChangeMe' -value '22'}
will add new property ChangeMe with value 22 to every item in this path:
hklm:\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}
Imposible is nothing