Offline and online, this game runs great on default settings (640x480, 32) on my old Core 2 Duo. No crash on Alt+Tab.

Computer:
Computer Type ACPI x86-based PC (Mobile)
Operating System Microsoft Windows 7 Ultimate
OS Service Pack Service Pack 1
Internet Explorer 9.11.9600.17358
DirectX DirectX 11.0
Computer Name -
User Name -
Logon Domain -
Date / Time 2014-10-20 / 16:55

Motherboard:
CPU Type Mobile DualCore Intel Pentium T2370, 1733 MHz (13 x 133)
Motherboard Name Acer Extensa 5620
Motherboard Chipset Intel Crestline-GML GL960
System Memory 2038 MB (DDR2-667 DDR2 SDRAM)
DIMM1: Samsung M4 70T2953EZ3-CE6 1 GB DDR2-667 DDR2 SDRAM (5-5-5-15 @ 333 MHz) (4-4-4-12 @ 266 MHz) (3-3-3-9 @ 200 MHz)
DIMM3: Samsung M4 70T2953EZ3-CE6 1 GB DDR2-667 DDR2 SDRAM (5-5-5-15 @ 333 MHz) (4-4-4-12 @ 266 MHz) (3-3-3-9 @ 200 MHz)
BIOS Type Phoenix (07/03/08)

Display:
Video Adapter Mobile Intel(R) 965 Express Chipset Family (384 MB)
Video Adapter Mobile Intel(R) 965 Express Chipset Family (384 MB)
3D Accelerator Intel GMA X3100
Monitor AU Optronics B154EW08 V0 [15.4" LCD]

Multimedia:
Audio Adapter Realtek ALC268 @ Intel 82801HBM ICH8M - High Definition Audio Controller