I wish to encrypt and decrypt a particular file on my laptop.
GPG4WIN seems to be ideal; however, I note that, when encrypting, I am given the option to ‘remove unencrypted original file when done’. How do I know that GPG4WIN has not simply deleted the original file - which could then of course easily be recovered using any freely available file restorer, making this application not really suitable for my purposes as I wish the encrypted file to be the only version available on my laptop?
Personally, I would shred the file myself or use a batch process to encrypt and then shred the old file. See this link for file shredding tools: http://www.thewindowsclub.com/delete-files-permanently-freeware-windows
Remove unencrypted original file when done calls the Windows system call to delete a file.
It will not move the file to some “waste bin” but it will also not put in an extra effort to make the file impossible to restore. This is out of scope for gpg4win and in most cases uneccessary.
Btw. the option to remove a file after encryption will probably be removed in future versions of gpg4win as I have a personal dislike against it 
(at least since https://bugs.g10code.com/gnupg/issue1624 )
a) There can be bugs (and there have been) that can cause Kleopatra to think the encryption worked fine if it actually did not. Combined with removal this makes it a data loss.
b) A bit of your reasoning. Some users understand by “remove” shred it overwrite it and put the disk where it was on in a microwave (kidding ) while others expect it to be recoverable from the waste bin. This is a usability dilemma.
c) It’s not that big of a comfort. Deleting a file through Windows is easy and then you can do it “the way you delete files on windows”.
d) It just makes bugs / usability that more critical if you deleted the original. (e.g. You did not encrypt to yourself by accident or bad usability in Kleopatra → bäm you can’t access your precious data anymore)
Andre,
could’nt we imagine an option to shred a file in Kleopatra, meaning encrypt it with an strong unknown random key. Then the resulting file will unreadable for anybody. Of course it would then be under the user’s responsibility to check, before using this option, that the original file was properly encrypted.