Si es un tema de configuración regional del windows, de todas maneras encontré esto por ahi
Cita: I had the same problem, and wasted almost a day or so on it. Finally, I found a very simple solution, namely to uninstall WAMP Server (version 2.1), and install a newer version (WampServer 2.1e - 32 bits). It's strange, but it solved the problem completely
Qué versión usas?, No será eso?