Hii Friends,

I have vista home installed on my lap top.I want to downgrade to xp professional,but when I insert my xp cd it shows harddisk not available.
How can I format the complete primary partition and make a fresh intall of xp.
Since I am not that very techie please guide me step wise.

I asked to the service center they told me to use external floppy drive to disable SATA .can i do it with the help of cd rom ? How?

thanks a lot.

It sounds like the laptop has a SATA controller and therefore disk, and there is no in-box driver for the controller on the XP CD (bear in mind the OS came out years before SATA existed, so it's not unusual).

You would need to find the SATA controller driver for Windows XP for the laptop on the manufacturer's website, and copy it to a floppy disk.

From the comment about an external floppy disk drive, I assume they mean the laptop has no internal floppy drive?

Then you would need to boot from the XP CD and hit F6 when prompted and insert the floppy disk with the driver present - this will allow Setup to see the hard disk and write to it.

However, if you are not very techy then you might want to reconsider the manual OS downgrade - you may have issues finding drivers for the rest of the hardware (display, network, chipset, touchpad peripherals typically).
It would be much better if the vendor could supply the laptop with the OS downgraded (complete with appropriate recovery CD), if they provide that service.

[Moving to XP forum as this is not related to Vista.]

You need to run fixmbr, because the mfat partition table and boot image in vista isnt compatible with pre-vista ones. Luckily you could do that while inside vista, then reboot with xp cd inserted, and do your thing.

In the manufacturer web site i could find a zipped forder called sata driver.zip
It contains the files
iaahci.cat , iaahci.inf , iastor.cat , iastor.inf ,iastor.sys ,txtsetup.oem

are these the files that I need to copy to floppy directly.

there i no exe file.??

Yes those are the files you need, if you can put them on an external floppy.