On a number of occasions over the past few months we have come across PCs that required a full reinstall of the operating system but the customer could not locate the discs that came with the PC. Depending on the brand of PC that you have, the absence of the manufacturers discs can be a problem. If your operating system becomes corrupt there are basically three ways that a manufacturer can allow you to restore it to normal.
The first is the way that Dell used to do it up until the last number of months. That is they supply you with a Windows XP installation disc and this can be used to reinstall the operating system. To do a full reinstall this way involves reformatting the hard disc drive, which wipes all your data and programs from the disc. So, once the operating system is reinstalled from the installation disc you then need to install device drivers for the hardware (chipset, graphics card, video card, modem, network adapter etc.). These drivers come on a second Dell CD usually labelled the Resource CD. If your PC is a Dell and it came with these discs then you should keep the discs in a safe place. However, if you cannot find them it isn't the end of the world. The operating system disc is generic so you can use the disc that came with another Dell PC, perhaps a friend has one. The Resource CD is not generic but is specific to your Dell model. However, even if you have lost this CD, you can download the drivers for your specific model from the Dell website by entering the service tag number for your PC on their Online Technical Support Page.
The second way that a manufacturer can allow you to recover your operating system is the way that current Dells, Packard Bells, IBMs and others do it. These PCs have a separate partition on the hard disc, which may be hidden, which contains an image of your system as it was supplied to you by the manufacturer. An image is like a digital snapshot of your system at a point in time and it will contain both the operating system, system drivers and any application software supplied by the manufacturer. To restore the PC to its as-new status a restore routine is invoked. This can be, depending on the manufacturer, by pressing a button such as F11 at startup or by using a System Restore disc that you boot the PC from. The advantage of this system of restoring your PC is that it restores not only the operating system, but also the drivers and supplied application software. The disadvantage is that if your hard disc becomes damaged, or you inadvertently deleted the recovery partition, you will have to go back to the manufacturer and see if they will supply a recovery DVD. If they will, they will charge you for it and it may take some time before you get it.
The third method of recovering your PC is using a recovery DVD. This is similar in principle to the second method, but the disk image is on one or more DVDs instead of a recovery partition on your hard disc. Compaq and Hewlett Packard PCs come with recovery DVDs and you do not want to lose these discs as they are specific to your machine and you cannot recover your machine without them. If you lose them, it is possible to get replacements but it may take you some time to get them and there will be a charge.