Hi Neko,
PI 3.0 should run fine on XP Pro and XP Home. It won't run on XP Media center or below since it uses the .NET Framework 4.0.
Your hardware should be okay, as long as it has the minimum recommended specs: 1GHz CPU, 512MB RAM, 600MB free disk space (if you don't have .NET 4.0). If you already have .NET Framework 4.0 on your machine then you'll need less than 10MB of free space.
Yes, many systems rely on reversion to the mean, but the implementations differ.
PI's Value Trading Algorithm actually uses a modified version of that concept by looking at groups of highly-correlated equities and trading based on their relative values -- rather than simply relying on a strict reversion to the mean. Therefore stocks may never actually revert to their individual means but you would end up trading around the group's (or a sub-group of that group's) mean.
Value investing and AIM loosely follow the reversion to the mean concept too, but, again, the implementations are different.
I hope that helps. Let me know if you have any other questions.
