Really? What specifications does it have? What version of Pro Tools are you running, and what type of interface are you using (mbox, 001, 002, etc)?
I haven't really used Pro Tools on a PC, but I know that Macs are really reliable. But with any machine, you do have to KNOW your machine to be able to run it. Very often you have to restart before using, or reset your ram by pushing a couple of keys on the mac (rare) or deleting some incompatible software that competes with others, and some people don't know to turn off all other software while running Pro Tools, especially all the little things that run in the bottom right corner of your PC that eat up ram.
Someone mentioned that you get so much more free stuff on PCs, but people tend to download them and make their PC a powerhouse to handle everything from Porn to Final Cut Pro. Some advice: Use your computer strictly for Pro Tools, and limit what else you have. If anything's questionable, read up on compatibility issues.
In terms of hardware vs. software, I prefer software simply because there are so many shortcuts and algorithms that were made to make magic in a matter of seconds. But if you're a recording buff like me, then you appreciate both, because you need hardware several steps along the way. And the top-of-the-line consoles (SSL and Neve) have the sickest software in them for taking snapshots of the mix and fader moves. True, these things cost as much as a decent-size house, but this is the beauty of where hardware and software collide.
And they STILL crash! I've been in music sessions with important clients, and the engineer will be making a mix and then lose ALL his work. Not the files; the Pro Tools systems seemed fine at the time, but every fader move and EQ setting and send were GONE.
Damn I ranted... whoever reads this is really bored.
Anyway... If you have software, it's up to you to KNOW your software. Know the limitations of your RAM and processor, and why it works for other people. Go on forums like duc.digidesign.com and ask questions and search for related posts. I went through a lazy spell myself, where I learned the LEAST amount that I needed to learn and EXPECTED IT TO WORK immediately out-of-the-box.
It is only after mistakes that we learn how to make headway. For any new producers/beatmakers: be prepared to make these mistakes and be ready to put up with them and you'll have to be strong enough to move on. Not to mention all the critics out there who tell you that your sh%t sucks and to stop and move back to Montana. Keep doin what you was doin when you was doin it.