It is advisable that you download and backup all update drivers for your System and also peripherals before you go ahead and restore or upgrade your Operating System In the event that your system is used for business i would sugest a professional do this for you but if you want to DIY thats ok its your PC. I advise this in the event that drivers or software is not available for printer scanner etcetera.
Ok here you go.
"Any one please correct me if i left any thing out".
BOLD normal drive old standard to start with follow these instructions
are you running SATA Serial ATA Hard drives or standard IDE/PATA or Paralell ATA if you are running a
new generation SATA Serial ATA Hard disk Drive make sure you have the drivers for these available on a floppy disk as in windows xp these are not native. If you have an old type wich are just as good barely different except fot the connectors you windows instalatin will run by only
change boot from cdrom in your BIOS and selecting to boot from your cdrom drive.When your system starts hit delete a few times as soon as boot screen apears almost as soon as you boot the PC. this will let you enter the BIOS/(Basic Input Output System) Once there go into where you drives are visible and chose the first boot device as a CDROM or DVDROM Drive press f10 and enter your system will restart This has to be reversed once the total install is finished.
Put the Windows Xp CD into your drive before the reeboot.
the system will reeboot and ask you to hit any key to boot from cdrom so press enter when this displays. the computer will then display press F6 if you need to load a third party driver for scsi device . So Hit F6 let the files and driver load. A screen will appear asking you to load drivers for your scsi or third party drive /device on the bottom of the screen you will be presented with options from there. if and when you get to the agreement hit F8 for accept EULA(End User License Agreement) Your drive/s will be displayed.
Select the drive you would like to install XP on then delete it then hit escape and you wil be presented with raw drives select one of these using your arrow keys on the keyboard and press enter Windows setup will ask you if you would like to quick format or other i sugest as you want a good clean install let windows setup fully format in NTFS file system just incase you are presented withth eoption FAT32 wich means a 32 BIT file alocation table this is old standard I sugest select the NTFS

New Technology File system

. it is much more stable.

yep it sure is. any way your computer will restart a few times during install and windows will/should then show you the rest of the way.
Recomend a minimum of 256mb Recomended 512 MB System memory
Minimum 64mb Graphics Memory I recommend 128mb or higher.
Minimum 40GB Hard Drive.