webhosts are only responsible to an extent, if you rent a dedicated server (which would be no suprise for a large site) they don't maintain software, user accounts, provide backups, etc.
As for finding out if MySQL and PHP are installed, thats not too hard in say linux (as you can just login via SSH and issue: which php and service mysqld status) however you're on windows, so you'd have to check the installed services (should whatever version allow you to easily do such), people can install things in all sorts of weird places on windows lol...
However, finding out the username for mysql will be a problem, as items aren't stored as plaintext and i don't know many admins who leave the passwords blank... though with knowledgeone can reset the mysql passwords but it takes a while... As it's windows, I woudln't know where to start, if it where a linux machine it'd be a sinch...
Normally I'd state that you should hire a server tech to take a look at things, but most that I know (myself included) don't deal with windows webhosting environments...
