i accidently wiped my hard drive of the os and dont have a boot up disk how can i restore it to factory settings?

What you probably have done is deleted just the main boot record (MBR: http://en.wikipedia.org/wiki/Master_boot_record). In that case it is possible to restore it

Editing/replacing MBR contents

Though it is possible to manipulate the bytes in the MBR sector directly using various disk editors, there are tools to write fixed sets of functioning code to the MBR. Since MS-DOS 5.0, the program FDISK has included the switch /MBR, which will rewrite the MBR code.[36] Under Windows 2000 and Windows XP, the Recovery Console can be used to write new MBR code to a storage device using its fixmbr command. Under Windows Vista and Windows 7, the Recovery Environment can be used to write new MBR code using the BOOTREC /FIXMBR command. Some third-party utilities may also be used for directly editing the contents of partition tables (without requiring any knowledge of hexadecimal or disk/sector editors), such as MBRWizard.[j]

dd is also a commonly used POSIX command to read or write to any location on a storage device, MBR included. In Linux, ms-sys may be used to install a Windows MBR. The GRUB and LILO projects have tools for writing code to the MBR sector, namely grub-install and lilo -mbr. The GRUB Legacy interactive console can write to the MBR, using the setup and embed commands, but GRUB2 currently requires grub-install to be run from within an operating system.

Various programs are able to create a "backup" of both the primary partition table and the logical partitions in the extended partition.

Linux sfdisk (on a SystemRescueCD) is able to save a backup of the primary and extended partition table. It creates a file that can be read in a text editor, or this file can be used by sfdisk to restore the primary/extended partition table. An example command to back up the partition table is sfdisk -d /dev/hda > hda.out and to restore is sfdisk /dev/hda < hda.out. It is possible to copy the partition table from one disk to another this way, useful for setting up mirroring, but it should be noted that sfdisk executes the command without prompting/warnings using sfdisk -d /dev/sda | sfdisk /dev/sdb.[37]





If you use the partition of your laptop reserved for restoring your OS, then it might wipe out all data that you have created since first time you started your laptop and re-install everything to factory default. It is possible to use a LiveCD (or USB) with some kind of Linux distro (you have look up that yourself) to enter Windows OS filesystem and move important data to another harddisk.

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Could you describe more in detail what happened that lead you to think that you might need to re-install windows on your laptop?