Which operating system are you using? What type of internet connection do you have (broadband, dial-up, etc.) and how are you trying to load Netscape? (From a desktop link or is it starting up when you log on to your dial-up connection?)
If you're trying to load Netscape from a desktop link, have you tried accessing the actual program from Windows Explorer? Maybe the link has simply become corrupted and needs to be recreated.
Hope this helps and let us know more.
My XP Professional system now does not load Netscape 7.2 after a few months of fairly trouble-free use. But it loads Netscape 7.0. But repeatedly does not load the 7.2 version.