Trouble Installing Windows XP from Vista

I bought a HP laptop yesterday with Windows Vista (I couldn't find any in the store with XP) and I've already had problems. While the laptop seems to be connecting to my LAN cable (getting the blinking orange light and the green light on the laptop itself and the PC activity light is blinking on the modem), when I try to install Comcast High Speed Internet on the computer, I receive a message that the LAN cable is not connected.

I've rebooted, unplugged the modem and left it alone for awhile before trying again, and I always arrive at the same result. Now the LAN cable works fine with my old desktop that runs with XP, so I think it is a problem with Vista.

I'm at the point (and after reading a lot of other complaints about the OS) that I just want to install XP on this new laptop except that when I attempt to do so, the "Install Windows XP" option is grayed out, and clicking on it only presents me with a hope crushing beep.

I can't get on the internet with Vista on this new computer, so I can't even begin to install drivers. I also seem to be unaable to go back to Windows XP. Now the Windows XP CD I'm using is old, could that be the problem? It recognizes other options on the CD, just not "Install Windows XP"

What are my options? This is incredibly frustrating.

Thanks for your time.

By the way, the version of Windows XP I'm trying to install is 2002, Service Pack 1.

It sounds to me like you are trying to run the Windows XP disc from within Vista. This is not possible. You must boot from your Windows XP Disc and install from there. You have two choices at that point. You can either wipe out your existing Vista install and just run XP or you can Dual boot with XP and Vista. If you decide you wish to dual boot, you will need to perform some steps to make Vista show up when choosing your OS at bootup.

Here is a good guide for Installing XP for Dual booting after already having Vista installed.

How to dual boot Vista and XP (with Vista installed first) -- the step-by-step guide | APC Magazine

Hope that helps.