You cannot install the no-cd patch for version 1.02 if you have not patched the game with the 9.6 patch. The exe file calls on information that is changed with the patch.
You can always check if the patch has been installed. If you go into the credits screen, your game should say that it is version 1.02. Also, do remember that installing the patch on a modded game is asking for big trouble. A unaltered game, or even better a clean install, is preferable.
As I see it you have two choices:
1) Either you rename your GP4 folder, and then reinstall the game in the folder you want. Then you delete the installation and rename you GP4 folder back to its old name. That way the registry settings are present and correct, and the patch should be able to find what it needs.
2) If you really can't get anything going, I would advise you to do the patching process yourself. Basically the patch is compressed with something similar to winrar or winace, and the installer is an elaborate version of a self-extractor. You can extract all the files with a program called Iscab and put them in the right location manually. It is a bit of a hassle but it should work.
You can get further information on Iscab here:
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www.grandprix3.com];
It's only after we've lost everything, that we are free to do anything.