Move files using rename doesn't work

[Terminator]

Hi,

We use IIS on Windows with PHP for our pages (yeah I know ... 😕 ), and now I want to move some files to a subdirectory using the rename function in PHP.
however this aint working

I use the following code

$path2textfiles = 'E:\Web\site\dir\\';
$path2move2 = 'E:\Web\site\dir\subdir\\';

if (rename($path2textfiles . $filename, $path2move2 . $filename)) {
					echo ">> Successfully moved <strong>" . $filename . ".</strong><br />";
}
else {
					echo ">> There was a problem moving <strong>" . $filename . "</strong>.<br />";
}

This will give me the message "There was a problem moving FILENAME"
The user IUSR_NAME has write, read and execute rights. Also I gave that account special rights (advanced on the security tab) as delete for "This Files".

I tried above path, also /dir/ and /dir/subdir/.

Any suggestions...