i have just bought new pc,so i want to put my old computer back to factory condition ,my hand book tells me i must remove any hardware i have installed since i bought it, i have installed a usb2 card so my printer etc could work faster do i need to manually remove it or can i just delete,also when its back to factory condition will my hard drive be clear of the contents i had on my pc many thanks in anticipation

First, you are wise to be concerned about this.

I don't see a need to remove the card, or to delete it (by it, I assume you mean the driver). That seems like a waste of time to me.

will my hard drive be clear of the contents i had on my pc

No. The unused locations on the hard drive that are not overwritten during the restore will still retain any data stored previously. This data can easily be retrieved by any number of disk inspection utilities. You really should "wipe" the drive first - a term used to describe the process of writing a bunch of ones and zeros over and over again, all across the drive, ensuring there is no residual magnetism holding any previously saved data. Then you re-install Windows, or use the recovery disks. I use Eraser.

my hand book tells me i must remove any hardware i have installed since i bought it, i have installed a usb2 card so my printer etc could work faster do i need to manually remove it or can i just delete

You have to remove the device from the machine. Many/most "factory restore" disks won't run if the hardware is different from when the machine left the factory. Modems, video cards, USB cards, etc, etc. Any different hardware.

Once you've done the above....

As far as clearing the hard disk, you could;

First, boot to the Windows XP recovery console. Description of the Windows XP Recovery Console for advanced users (See Option 2 or 3)

(This is not a required step, just make sure you have the correct hard disk if there is more than one hard disk in the machine.)

Inside the recovery console, type the command:

Map

and hit ENTER.

This will show what drives are on the system. The primary drive always starts as Disk 0, then Disk 1, and so on. You can also use diskpart to see what drives are on the system.

When ready, type:

mkdiskraw #
(# is the number of the drive you want to clear)

Hit ENTER.

This command will nuke your data, filesystem, partition table, and MBR all in one move.

After you've done this, start the factory restore on the blank hard disk.