wsh currentdirectory broken on Win 8.1? - hta

Question

We use HTA files to build installation CD's, so that we can display some introductory information and links to different setup options - each link goes to the appropriate setup.exe etc file. This has worked fine up to and including Windows 7, but on 8.1 (- not tried 8.0) it fails with an error 'Cannot find the file specified'. Turns out that this is because the current directory is now C:\Windows\System32, whereas it used to be the directory where the file was located - on the CD drive, and so relative paths would work for the links to the other files on the CD; now they don't.
In other words using this code in an hta file:
<script type="text/javascript" language="javascript">
function RunFile(appname)
{
WshShell = new ActiveXObject("WScript.Shell");
alert( WshShell.CurrentDirectory );
WshShell.Run(appname, 1, false);
}
on win 8.1 we see C:\Windows\System32 in the alert box and so relative paths such as ..\ourproduct\setup.exe no longer work.
Is this a bug? Any ideas how I can work around this?

Answer 1

You could extract the correct path from window.location.pathname, and then set the value to CurrentDirectory. I've used something like the code below:
var shell = new ActiveXObject('WScript.Shell'),
defaultInstallationFolder = 'installation_folder_name',
currentPath = window.location.pathname.replace(/\\/g,'/'),
defaultRootPath;
if (currentPath.charAt(0) === '/') { // For the browser environment
currentPath = currentPath.substring(1, currentPath.length);
}
currentPath = currentPath.split(defaultInstallationFolder);
defaultRootPath = currentPath[0] + defaultInstallationFolder;
shell.CurrentDirectory = defaultRootPath;
IE and HTA give a slightly different pathname (in IE it starts with /). Sometimes it's nice to debug a HTA in IE, hence the check for currentPath.