Trying to install Boot Camp Drivers on MacBook2,1 for Windows XP
The Boot Camp drivers for (really) old iMacs is included on the OS X Snow Leopard installation DVD. This DVD can still be purchased from Apple. Since Snow Leopard was released in 2009, the DVD should contain the XP drives for your 2006 Mac.

Since OS X Leopard was released on DVD in late 2007, the Boot Camp drivers on this DVD should also work with a XP installation on your Mac. 

Apple does have a Boot Camp - Windows XP Drivers Update 2.1 website which states the following:


  Note: This download contains complete copies of Boot Camp Windows XP Drivers (version 2.1).  If you have Boot Camp drivers already installed, it will update them.  If you do not have any Boot Camp drivers installed, it will install version 2.1 drivers onto your already installed Windows OS.


Since the Post Date is Apr 24, 2008 and the website mentions OS X Leopard, I would assume the download would contain the drivers for all 2006 Macs that can run Windows XP. The web site has a special note, which is repeated below.


  Important: Installation of Boot Camp 2.1 is required before installing Windows XP Service Pack 3 (SP3)


There is also a Boot Camp Drivers Update 2.2 for Windows. However, this does not appear to contain all the XP drivers. Therefore, this update should be applied after installing Boot Camp 2.1.