$re = '/\\\\AppData\\\\Local\\\\Temp\\\\[a-zA-Z0-9]{0,8}-[a-zA-Z0-9]{0,4}-[a-zA-Z0-9]{0,4}-[a-zA-Z0-9]{0,4}-[a-zA-Z0-9]{0,12}\\\\G2MInstaller.exe/m';
$str = 'C:\\Users\\PDELGADO~1\\AppData\\Local\\Temp\\8FFA79F7-BBCD-4D73-903C-B8A82FC482B0\\G2MInstaller.exe';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php