unlink() problem with PHP

Hy everybody. I am using PHP4.01 as CGI on IIS . The OS is NT. I am trying to erase some file using unlink() from a directory with access rights corectly set (read/write/execute). The error message i get is "unlink() is not supported under this build of PHP" (or something like this...). I have the corect manual for this build, and it doesn't mention anything about not suporting the unlink() function, so i guess the error message ie eronated :). I tried a different aproach of this situation, so i tried to delete the file using exec() & system() and it didn't worked. I would like to know if there is a different way to erase a file, create and remove a directory from within PHP or i have to use a different language (lige ASP..) for this task? Thank you. MMG