I'm running OS 9.1 on a g3. I have LW Pro 3.4.7 installed a few months back and works great. I also have a pc with LW Pro as well. When I went to open LWP on my pc I got a pop up that said there was a newer version of LW so I d loaded 3.6.15 Pro and I can see the interface was different from 3.4.7 and that works fine. So back to my Mac I d loaded the 3.6.15 Pro upgrade but when I installed and opened the app it looked the same as 3.4.7 and (in about) LW it says it's the 3.4.7 version. Did I do something wrong on the install?

Should have worked if it installed in the same location. Search the hard drive for two copies. If you only have one, I guess the older one should have been uninstalled first.

You may want to keep both, though, so backing up the old installer first might be a good idea.

Try this, Uninstall LimeWire and then re download the new version off the LimeWire website. You can use the download link in my signature. I hope this helps.