What are common challenges faced when dealing with file operations in PHP on Windows systems, especially with special characters like German umlauts?

When dealing with file operations in PHP on Windows systems, especially with special characters like German umlauts, a common challenge is encoding compatibility. To solve this issue, you can use the `utf8_encode()` function to convert the strings to UTF-8 encoding before performing file operations.

$file_path = 'C:\path\to\file\with\umlauts.txt';
$file_content = file_get_contents($file_path);
$file_content_utf8 = utf8_encode($file_content);

// Perform file operations with the UTF-8 encoded content
// For example, write the content back to the file
file_put_contents($file_path, $file_content_utf8);