WinRAR is the best since it works with all type files not just zip files. Its not free but does offer a fully functional trial which is free, what happens after is between you and your conscience. I put a link to a download below.
https://www.win-rar.com/start.html?&L=0I will assume you are semi computer literate and know how to open links from the (x86) program files, if not speak out and step by step can be added. This next step isn't necessary, but if not done your game will start taking longer and longer to load after your course folder grows to over a hundred courses since it scans your course folder upon start up.
Create a new folder inside links. Name it (courses 2k3), then move everything from your course folder to the newly created courses 2k3 folder EXCEPT the 2 driving files. The best way to accomplish this is to have both your course and courses 2k3 folders open side by side on your monitor and then just start dragging and dropping them in.
Once these steps have been completed create a new folder in your documents, name it whatever you want, and then unzip all the courses to that folder. Once that is complete then bring that folder and and your courses 2k3 folder up side by side on your monitor as before and start dragging and dropping them all in.
The last step is to get the game to see them so open links, click options,click course manager, click add, then when the next screen opens click the little yellow folder on the left above the drop box. Click the courses 2k3 which will be listed under the courses, then click the select all tab.
If you skipped creating the new courses folder all the courses will have probably appeared before the click the little yellow folder line.
You must exit the game after and restart before playing to lock all the courses into place.