I believe older Operating Systems are in fact more secure and run way faster than modern OS.
The only reason Windows 98 is considered less secure is because there may be security holes or vulnerabilities that cause attackers to get into your computer remotely (remote attack without authentication, generally). Other than that, many modern software will need a different computer architecture than offered by older operating systems.
Windows version 2000 or higher is in fact less secure than older versions. Why? Because it is the biggest target. If hackers and malware writers, companies and those interested in hacking computers are not focusing on the small percentage of people using an operating system, how can it be less secure?
Back in 2004, the Windows 2000 Source Code got leaked on the internet. Many people, even so called security experts failed to see what this caused even a decade later. EVERY windows since Windows 2000/NT, has been built on the exact same architecture and relies heavily on .net framework, which is shared by just about every modern program. Learning how post Windows 2000/NT operating systems worked and handled code, and especially how the kernel processed code execution and pass them to the CPU caused the first real wave of malware, spam and ransomware outbreaks.
Older operating systems are not affected by these attacks, simply because these older systems do not have the framework needed to allow the same code execution. Similar to 32bit OS rejecting the code of 64bit programs.
All in all, Older OS's like Windows 95/98/ME are more secure than newer operating systems. There are software that will protect you even more than running newer OS like Windows 7/8/10.
Here are a few tips:
- Create two computer accounts - Main User and Exec
- Delete or disable all default accounts - Admin, Administrator and Guest
- Set the Main User to only have basic run rights on the PC
- Set the Exec to have Administrative rights on the PC - Set a password as well.
- Install a free firewall like Tiny Personal Firewall and block EVERYTHING, except the programs you know you trust.
- DO NOT install antivirus programs. These programs have proven largely ineffective and can only work AFTER infection in most cases, and NEVER really cleans up all files.
- Use your computer for about a week then create a backup. Free backup programs all over. Norton ghost may work best for older computers (I think version 7)
- If you ever get a virus, you can simply restore your stuff.
- Save your files to a cloud drive or external drive. Never save important stuff to your C Drive.
I've ran this setup for years, and know it works.
EDIT - A little research goes a long way. Here are a few sources you can simply click on and read.
Also keep in mind that antivirus software are big targets as well, since they are sometimes touted as gate keepers of a computer system over a firewall. Imagine an antivirus getting hacked, how would you know?