Sadly the MAC crashes after sometimes a few minutes or an hour. The system blocks en the hourglass keeps turning. The only thing I can do is reboot the system.
I can move the mouse and click on the Icons, but no other programm starts.

Please help!

---

_____________________________________

CPU: AMD Athlon 64 3800+
Asus A8N-E
RAM: 2 x 1 GB
NVIDIA nForce 4 MCP
NIVIDIA GeForce 6600
Realtek AC'87 audio
Windows Vista
USB Harddisk Lacie 250 Gb with MAC OSx86 iPC Leopard 10.5.6