When I have downloaded a film through an ftp program like ARES and I then come to play the film I get an error message saying that windows explorer has encountered a problem and must shut down. I also get this message when I rest my mouse pointer on the film file. I am running windows xp pro. I hope you can help Thank you Ted

   That sounds like Data Execution Prevention.  Windows assumes those files are bad even though they probably are not and so it gives you that error.  There is more information at http://support.microsoft.com/kb/875352 about this.
   Data Execution Prevention is new in WinXP SP2 and is set up in the boot.ini file after the command, /noexecute.  Data Execution Prevention can be disabled by opening the boot.ini file in the C:\ directory and making sure that the /noexecute setting is followed by =AlwaysOff (so it would be /noexecute=AlwaysOff).

Thank you very much for your prompt reply. I shall put your suggestion into practice and let you know what happens. Thank you Ray

I cannot find 'boot.ini' can you please help, I feel so foolish!

   In Windows Explorer, go to the Tools menu and select Folder Options.  On the Folder Options window go to the View tab.  Uncheck the "Hide protected operating system files" checkbox and make sure the "Show hidden files and folders" item is marked.  Then click on the OK button.
   That should allow you to see the boot.ini file in C:\.

Thank you very much for your prompt reply, I have done what you said and all is working, and playing, as it should. Thank you for a very good service Ted.