“We have fixed the Win7 issues. I personally can run L2 for many hours, it’s never crashed for me (on Win7 64bit with a 2 year old graphics card and 4GB of ram). You can try launching L2.exe and then go to task manager (ctrl+shift+escape), find L2.exe in the processes tab and try to set affinity to only 1 core.”
That doesn’t solve the alt-tab problem, I just tried. And I agree with Verena. If I can’t quickly reply on skype or check something in my browser without crashing, i’m afraid I won’t play here :/