The problem is that the OP'd path excerpt not only had the \c\ version, which you are focusing on; it also had c:\strawberry\perl\bin, which is the full path used in the "that works fine" post, so if that really was the path, it should have been found.
Unfortunately, we've only ever seen that original snippet of anonypl's "path variable", and do not know whether that was a copy/paste from the windows "Environment Variables" dialog box (and if so, whether it was from the user variables or system variables section), or whether that was a partial copy/paste from the actual cmd.exe prompt, with either a path or an echo %PATH% issued.
I am curious whether powershell is finding the same perl executable that the full-path does from cmd.exe. If anonypl could run something similar to the following, we may learn more.
cmd.exe
C:\Users\pryrt>powershell
Windows PowerShell
Copyright (C) 2016 Microsoft Corporation. All rights reserved.
PS C:\Users\pryrt> (get-command perl.exe).path
c:\usr\local\apps\berrybrew\perls\5.24.0_64\perl\bin\perl.exe
PS C:\Users\pryrt> exit
C:\Users\pryrt>where perl
c:\usr\local\apps\berrybrew\perls\5.24.0_64\perl\bin\perl.exe
c:\usr\local\apps\berrybrew\perls\5.24.0_64\perl\bin\perl.exe
C:\Users\pryrt>echo %PATH%
...;c:\usr\local\apps\berrybrew\perls\5.24.0_64\c\bin;c:\usr\local\app
+s\berrybrew\perls\5.24.0_64\perl\bin;c:\usr\local\apps\berrybrew\perl
+s\5.24.0_64\perl\site\bin;...
And if you're wary of revealing something in your PATH, feel free to ellide, like I did. Or use the known location of perl to help you snip it, so we don't accuse you of deleting something helpful:
c:\usr\local\apps\berrybrew\perls\5.24.0_64\perl\bin\perl.exe -le "pri
+nt for grep { /perl/ } split /;/, $ENV{PATH}"
c:\usr\local\apps\berrybrew\perls\5.24.0_64\c\bin
c:\usr\local\apps\berrybrew\perls\5.24.0_64\perl\bin
c:\usr\local\apps\berrybrew\perls\5.24.0_64\perl\site\bin
Though on your system, you should use your known-good path to perl, which according to the aforementioned "works fine" post, should be as follows. Oh, right, and search for perl or berry:
C:\Strawberry\perl\bin\perl\perl.exe -le "print for grep { /perl|berr
+y/ } split /;/, $ENV{PATH}"
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