arguments against moving site from Linux/Apache/PHP server to Windows/IIS/PHP needed

Hi, I have to convince one guy to not move our site from Linux box where it runs with Apache/PHP + MySQL to Windows box where it's going to deal with Windows 2k/IIS/PHP(CGI) + MySQL and I need really good arguments, cause it's only way I can convince him (cause his position in company is much stronger than mine). I know that PHP under windows is intended to be used only as test platform, but this is not enough to convince him. Can you help me? I need some reasons like things that won't work under windows version of PHP (or at least MySQL) and that are not easy to fix. I've already found that IIS doesn't provide $_SERVER["DOCUMENT_ROOT"] but it's not too much work to fix that.. Please help! Big thanks in advance! Sebastian