Uploading large files

Hi, i have a form for uploading files to a server. It looks like this: <form action="upload.php" method="post" enctype="multipart/form-data"> <input type="file" name="name"> <input type="submit" value="Go"> </form> Whenever I choose a file bigger than about 4 or 5 MB i get an internal server error. I changed the values for post_max_size, upload_max_file_size and max_execution_time in php.ini - without any success. Does anyone knows why? I am running php 4.0.6 on Win98 SE and Apache 1.3.12 Thanks, Uli