[Disk_Contented]

Hmmm. Let's get one thing straight. Absolutely anything is an improvement on Vista. The OS isn't even finished yet. I suggest it is a public beta.

If you want absolute compatability, stick with XP. It's the best M$ has to offer. Linux has wine, but a virtual machine is a vastly better idea. You get to run both OS at the same time. No good for games or intensive apps really though.

Linux isn't for the faint hearted, no matter what people say. You will find the transition from windows difficult, to put it mildly.

I'm experimenting with mac OS at the moment. So from a Mac noob point of view...
I will switch to this OS if my experience shows it a viable alternative to XP.

First off, Macs now run on PC hardware.
OS X will run on fairly modern PC hardware, as long as SSE2 instructions at least, are supported by the CPU. SSE3 is better.
Again, not for the faint hearted. The probability of failure is high, and you need a "special" version of the OS to make it work.

The best thing to do is reinstall XP. It's not that bad. Install "VMware workstation" and install linux on that. You get to experiment to your hearts content without destroying your system and you can try as many different versions of linux as you wish. Should you find a version you like, you can even dual boot it with XP for those times you have to run a windows app.