2 questions about IDES installation from a freshman

Hi all:

I am a freshman in SAP and since our company is going to use SAP BI, I want to install EDIS ECC6.0 and BW on my computer.

Here I have 2 quesions:

1. Can I install ECC with an external USB portable hard disk(1TB)?

If so, here I have 2 computers, Can anybody kindly suggest which one is better?(A new computer is not a good choice because I don't want to be killed by my mum...)

Option 1: Laptop A

CPU: Intel Pentium M(Dothan) 740

Memory: 2G

Hard Disk: 120G + 1TB portable hard disk

Option 2: Desktop B

CPU: Intel P4 2.8G

Memory: 512MB(Memory is not a problem, I can buy a new one)

Hard Disk: 60G + 1TB portable hard disk

2. Can I install IDES on Windows XP SP2?

Best Regrds

Tim