Before you begin to reinstall the system, care should be taken to preserve the information. Carefully review the contents of the drive on which you are going to put the system (for these purposes, it is recommended that the C drive). If it has files you need in the future (for example, the folder My documents, Inbox, pictures, movies, etc.), transfer them to other media. Better if it is a portable hard disk, DVD, flash drive sufficient volume. In extreme cases, move the data to another logical drive (D, E...) that you do not plan to format.Prepare a CD or DVD (depending on the drive) boot disk and driver disks for the hardware that is installed on the computer. Record system information, computer name in the system account, etc.
You can now reinstall the system. To do this, insert the boot disk. Configure the BIOS so that loading begins with CD-ROM. At the beginning of the boot by pressing del/F2 to log in the main window, make the desired settings (in the item "First Boot Device" should be the value of "CDROM"). Then, click on "Save and exit" or F10, exit BIOS. The computer will start to boot from the disk.
Before you – the main installation menu, select the desired item. Now you need to be very careful, because the installer will ask you about the space on your hard disk where you put system. This section will be asked to format. You must not hurry, think carefully about the answers, otherwise you can lose all the information on the computer. Unless of course you decide to start from a blank sheet, format all partitions. For better performance it is recommended to format all drives with NTFS. Selecting to install the partition, specify its size. It depends on the overall size of the hard drive and installed (so Windows XP is recommended at least 10 GB, if more is better). The remaining disk space can smash at their own discretion.The next phase of work directly installation. To touch anything it is not necessary to intervene only when there is a specific request from the program. At this stage you can enter network settings, computer name, etc. In that case, if you doubt the correctness of the information requested, ignore the issue, press Continue.
Within half an hour, the system will be installed on your computer. In recent builds the boot disks provided to install basic working drivers. That is why almost immediately you will have a workable system. Installing missing drivers, start to restore your programs, settings.
If there is no desire or skill to understand the contents of the C drive, copy to a backup disk folder "Documents and Settings" as a whole.