Help needed with Bootcamp

[gazfocus]

I have installed Windows XP using Bootcamp on my iMac at work but whenever I hold down the option key when the iMac boots, it doesn't give the option to boot to Windows.

When's the right time to press the option key?

[tersono]

Hold down option immediately on system turn-on.

Just a thought, but you did reformat the drive from the XP installer, not just from boot camp, yes? If you didn't, you'll need to re-install as the partition won't be bootable.