Internet Explorer lets in far too much spyware/malware. Netscape is a crappy thing that installs too much 'extras'. Mozilla/Firefox are very good browsers, but unfortunately don't display all web pages correctly.

The best combination is to use Mozilla/Firefox as a main browser, and Internet Explorer only for those sites which need it.

Windows 98 is nowhere near as good as Windows XP, but your system needs to be powerfully enough configured to make use of it. On an old, underpowered, limited RAM system it runs like a dog!