Set up for new computer wants the security key Where do I find this?

[Guest]

Hello,
How do I get my "security key"? I have 2 computers and bought an Acer Aspire. It needs the Security Key? Please help. I have no idea what it is or how to find it. Thank you!

 

[Guest]

This looks like a reasonable explanation:

http://www.tomshardware.co.uk/forum/27978-18-tomshardware