Error: Unable to fork (PHP 4.21)

I've searched the entire archives and google for a solution to this. There are plenty of references to the "Unable to fork" error.. most having to do with a bug in PHP 4.02. I writing the script for a remote Windows server running PHP 4.21 so the bug shouldn't be a problem.. I can only assume I am not doing it correctly. The script simply needs to convert a file using ImageMagick stored in c:\Program Files\ImageMagick... I've tried.. $cmd = "c:\\Program Files\\ImageMagick\\convert -quality 80 -antialias -sample '".$x."x".$y."' '$obj' '$dest'"; system($cmd); And on a tip that I found in the list archives I tried.. $cmd = "convert /c dir c:\\Program Files\\ImageMagick -quality 80 -antialias -sample '".$x."x".$y."' '$obj' '$dest'"; system($cmd); Both return Unable to Fork errors.. Warning: Unable to fork [convert /c dir c:\Program Files\ImageMagick -quality 80 -antialias -sample '320x240' 'C:\PHP\uploadtemp\php43.tmp' 'e:/NLObjects/thumb.jpg'] in c:\inetpub\wwwroot\exchange_tmp\uploadtest.php on line 72 I have used ImageMagick successfully on a UNIX server. But I didn't have to specify the location of the convert tool. This is Windows server and I really don't have a clue if I am doing this correctly. Any help will be greatly appreciated. -Kevin