The first time I used a Linux was on a AMD K6 II machine. It probably was around 266Mhz or so with 64MB RAM. I think it had a 2GB hard drive. I think I installed Slackware Linux, I don't really remember for sure.
I had no experience at Linux at that time, and wondered what "root" was and all. I couldn't even "startx"! :)
It was a start of my Linux adventure.
The next time I installed Linux was on a 80GB hard drive on my dad's Dell Inspiron 8200 laptop. It had 1.7Ghz Pentium 4-M CPU on it, and I installed Ubuntu. I played around on it for a while, configuring wifi cards and all, and surfing the net on it was a fun experience. The Ubuntu was later wiped and I installed Windows XP again and it is sometimes used by me and my dad.
I now have five computers running Linux.
One is Macbook Pro bought in 2009, used with VirtualBox running several flavors of Linux. I installed Chromium OS, Ubuntu, and Cloudera's Ubuntu for trying out Hadoop.
Two more are HP Proliant ML115, with one running a Phenom II X4 2.6Ghz CPU, 2GB RAM and 32GB SSD from Patriot. It runs CentOS 5.5.
Another HP Proliant ML115 has the stock 2.7Ghz single core CPU, and a Geforce GT220 512MB DDR2. I used to have Geforce 210 512MB with DDR3 on it. It's not in use at the moment, but will be revived soon. This runs CentOS 5.5.
Last December, I made a computer from parts I bought at Dospara, and it has 3.2GHz Athlon II X2, 8GB DDR3 memory, and 1TB hard drive. I used a ASUS motherboard, and I installed CentOS 5.5. It is currently used to power my search engine, Mohawk.
I currently use VMware Player on my Vaio Z running WIndows 7, and it runs Cloudera's Ubuntu. It is configured so it uses 2 cores by editing the setting. I mainly use this for testing out Perl programs on the go. Vaio Z runs the virtual Linux very smoothly because it has been upgraded to 8GB DDR3 memory a while back.
Well, that's all of my computers running Linux, and I have used Cygwin in the past, but I like a regular Linux better.