Moreover, the "programs" floating around the web are written in uncertain way and their working might depend on many unknown variables. Unfortunately, they usually don't provide any means for testing and setting up; they simply assume "it works as I tried it and it worked". This is an approach which results in uncertainties you are facing now.

Don't get fooled by "it works for me" from many people. Please realize there are zillions of combinations of cables/parallel port chips/motherboards/windows drivers and other related system programs/etc. All of these may play its role in success of such "design". Those for whom it did not work often don't say it out aloud.

I am not in favour of proposing to buy a cable as I know very well it's not easy nor cheap for you; nevertheless once the "rusty nail" approach failed (it might have worked but it did not), I'd recommend better to give it up and either to search for some programmer on more solid grounds (e.g. asking somebody in your vicinity with a proven good programmer), or to look for - more expensive, I admit - chips providing ISP via UART (e.g. the 'RD2s).

JW