Windows 7: How do i Dual-Boot Win7Ult and XP?

Title says it.
How? Complete newbie, never partioned, dual-booted or anything like that.
Hard Drive is... 282 size, 236 free.
How? I NEED MY TRUSTY Windows 7!

You think it might be a good idea to tell us which OS is already on the PC?

Follow these steps to Dual Boot Installation with Windows 7 and XP

Windows 7 is already on.

Option Two of tutorial above.

First check for all the Win XP drivers for your hardware.
You can check your HP/compaq PC here:
General XP Downgrade Guide for HP Laptops - HP Support Forum
NOTE: Please read this thread fully.

Then shrink the Windows 7 partition enough for your XP partition, boot the XP CD, create and full format the partition. If the HD is not seen by the XP CD then you'll have to provide SATA Drivers - Slipstream into Windows XP CD.

Once XP starts up the easiest way now on modern hardware is to mark Windows 7 partition Active and run Startup Repair - Run up to 3 Separate Times to restart Windows 7, then install EasyBCD (click Download - no Name or Email required) to add XP on it's Add OS Entry tab. Accept offered XP boot files, Save, reboot to Dual Boot Menu.

Brilliant, thanks!
I can go on XP too now!

Good work.