i want to reformat my PC. it is in windows XP service pack 2, i want it to change in service pack 3.. but i can't seem to reformat my PC.. when i inserted the CD of SP3 and reboot my PC, it did not direct me to "press any key to boot from CD".. i changed the settings in BIOS that i made CD-ROM as the first to boot but it still did not work... it always the welcome note of windows XP that is shown to my monitor.. what should i do??? pls help me.. just send me a private message if you want.. thank you.!!!

Sounds like your CD isn't bootable. Make a bootable XP CD or boot to another bootable cd and run the XP setup from that environment.

Is that CD actually an XP install disk with SP3 included, or just the SP3 update?

Most probably your CD is not 'Bootable' as said by 'HoustonIT'..Which OS is it XP home or Pro?? Why don't you just update from the net, if its XP pro then the update file is approx 316 MB, else fetch a bootable disc which i guess will also mean formatting the partition to clear traces of the current SP, not sure if the disc has an update option apart from repair which may not be much accurate..