There are a couple of things that can cause problems if the tutorials do not meniton it. On is if you are using an AHCI controller for you hard drives. XP does not know what it is so you will need to have a driver and you will probalby need a floppy to load it. If you get a blue screen, this is more than likely your problem. I do not know if the later versions of XP corrected the problem.
Also, if the tutorial talks about XP overwritting the Win 7 boot code, pay close attention on how to get it back.
Are you using SATA drives?. The AHCI problem will only occur with them. But, in the event, perhaps, before you start, it would be wise to grab the SATA/AHCI software and, as Saltgrass suggests, put them on another media. There are tuturials on the web as to how to "slipstream" them on to a XP installation CD, but that would be a long way round. Fwiw. Here is a page where you can have a look for the needed drivers http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&keyword=%22ahci+sata+driver%22
" pay close attention on how to get it back" Wise words. You may lose your Internet access. Best print out that beautiful tutorial.
hi thanks for your responses im formatting other ppl computers and sometimes they want both xp and win 7 so some them have sata and some IDE i just dont get it why it is so compicated i was sure all i have to do is just insert the XP cd and then pick install without any format\adding new partition and when i start the computer it will let me choose xp or win 7 but it seem much complicated then that somehow
It sur is. If you do as you say, the chances are, you not having SATA, is that XP will install. You will then have the task of trying to rewrite the startup manager, so that you can boot Windows 7. But, reading your posts so far, I must remind you that you will need another partition or HD. The two OSs cannot reside on the same media (or partition).