I am using XP professional at the moment. My college is offering me a free software but I am not sure which version of Windows 7 to choose. 32 or 64 bit? Did anyone have experience with this combination of processor and OS?

Computer Type ACPI Uniprocessor PC
Operating System Microsoft Windows XP Professional
OS Service Pack Service Pack 3
CPU Type AMD Athlon 64, 2000 MHz (10 x 200) 3000+
Motherboard Name Asus K8N4-E (3 PCI, 3 PCI-E x1, 1 PCI-E x16, 3 DDR DIMM, Audio, Gigabit LAN)
Motherboard Chipset nVIDIA nForce4-4X, AMD Hammer
System Memory 1536 MB (PC3200 DDR SDRAM)
DIMM1: Kingston K 512 MB PC3200 DDR SDRAM (3.0-3-3-8 @ 200 MHz) (2.5-3-3-7 @ 166 MHz) (2.0-2-2-6 @ 133 MHz)
DIMM2: Kingston K 1 GB PC3200 DDR SDRAM (3.0-3-3-8 @ 200 MHz) (2.5-3-3-7 @ 166 MHz)

The CPU is the only requirement needed to run a 64-bit OS, all Athlon 64 processors support it.
However, given your comp specs, I don't think you would benefit with the increased speed of a 64-bit OS.
Windows 7 32-bit should be perfectly fine for your needs.

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