|"Can I install Win xp in my laptop?"|
Why would you want to?
To be able to install XP, you'll have to do a lot of prep work. XP doesn't natively support SATA hard drives so you'll have to come up with a way to install the SATA drivers during the XP install. As an alternative, you *may* be able to change the BIOS settings to IDE compatibility mode, then install XP. After the XP install is completed, you can install the SATA drivers, then go back into the BIOS & change IDE compatibility mode back to SATA mode.
You will also have to come up with XP compatible drivers for the chipset, sound, video, network, etc. It's doubtful these drivers will be included on the disc because XP is from 2002 & your hardware is most likely much newer. It will be MUCH easier to identify your hardware thru Win 7's device manager.
So once you've decided on a method to bypass the SATA issue AND collected all the necessary XP compatible device drivers, then you can attempt to install XP.