alternative operating system?

OpenBSD (which isn't Linux, but both are based on Unix) installed very smoothly for me on an IBM thinkpad; however, installing KDE or Gnome were a little troublesome. There are various flavors of Linux that can hold their own against Microsoft, but they still have some work to do with compatibility and other than Ubuntu Linux, which was very easy to install (and would be for a newbie) with a desktop environment preinstalled, installation of BSD and Linux still give a lot more trouble for a beginner.

So, what I'm saying is, as far as a contender is concerned that isn't Windows or Linux based, I can only suggest OpenBSD, but you'd better be ready to do some serious fiddling to get a desktop environment working the way you'd like. OpenBSD still has a long way to go before the standard end user will find it on par, if not superior to Windows, MacOS, or Ubuntu.

If I knew more about Solaris and Red Hat I'd say something about them.

It depends on WHAT you need the system for, whether programing is available or you can write it, etc. (Even your microwave has a "computer" in it.)

I still use DOS for some things, like control of my amateur radio station.

The programing was available or easily written, AND the system is up and running and ready to transmit in 20 seconds from power on.(All this with a 33Mhz bus, 200Mhz CPU, 16Mb RAM, and 500Mb Hard drive!!)

My XP system hasn't even gotten to the log-in screen in that time.

(I have 9 systems at this time and 1 of those has 3 different OS's on it!)