Unable to fork

Hi, I'm trying to execute a program in an WinNT/IIS server using PHP. The command line that I pass works fine from the DOS CmdPrompt but not via the PHP. The code that I use is: '--------------------------------- <?php print("Begin at: " . (string)time() . "<BR><BR>"); $temp=escapeshellcmd("mm.exe test.mpg test3.mpg test3"); print($temp . "<BR><BR>" ); echo(exec($temp)); echo(passthru($temp)); echo(system($temp)); print("<BR><BR>End at: " . (string)time()); ?> '--------------------------------- and the result on the browser: '--------------------------------- Begin at: 974279375 mm.exe test.mpg test3.mpg test3 Warning: Unable to fork [mm.exe test.mpg test3.mpg test3] in c:\inetpub\ecomroot\stratos\mm\testexec.php on line 6 Warning: Unable to fork [mm.exe test.mpg test3.mpg test3] in c:\inetpub\ecomroot\stratos\mm\testexec.php on line 7 Warning: Unable to fork [mm.exe test.mpg test3.mpg test3] in c:\inetpub\ecomroot\stratos\mm\testexec.php on line 8 End at: 974279375 '--------------------------------- Can anyone see what I'm doing wrong or if special confinguration is required? Any suggestions are greatly appreciated. TIA Stratos