I can't post my msinfo and dxdiag at the moment because I'm a work, but here are my system specs:
Windows XP SP2
Intel Celeron D 3.06ghz
Geforce 6600 256 meg graphics card
2 Gigs ram running dual channel
Problem:
After approximately 6 hours of being logged in, the game closed with an "out of virtual memory" error. Now, I'm aware that 6 hours is a long time to be logged in, but obviously with 2 gigs of ram and a 4 gig pagefile...I don't expect to be running low on virtual memory regardless of how long I'm logged in. I immediately logged back in without rebooting the computer, and crashed again 20 minutes later with no error message.
In addition to that crash the lag when loading textures, like when I first enter an area, is ridiculous. If I can run Everquest (I play daily), with it's antiquated and inefficient coding, with little to no lag on nearly top end settings, it's reasonable to assume I should be able to run Horizons with little to no lag on near bottom end settings.