"our sysadmin tried to dis-associate them, but couldn't"
what is the world coming to.
open a windows-explorer, go to a directory with PHP files in it, hold down shift, right click the php file, and choose 'open with'
PS, I'm not supposed to tell you this because it's only for the super-intelligent;
but there is a hidden feature in windows, called a 'help file'. If you press F1 you'll get the hidden interface...
:-)