In all situations where I've worked with Vista, a full wipe of the drive with a program like Dban or Killdisk is necessary to get XP to install correctly.
http://dban.sourceforge.net/
http://www.killdisk.com/
Hope this helps.
Grif
I need help fixing my friends comptuter. He clean installed Windows Vista, messed with it a while, then decided to dual boot. He reinstalled Windows XP Media Center addiction (which came with his pc and we used the sticker on the side of the case for installation) on a partition. After changing a boot menu option, he could dual boot fine, but had no internet connection. He wanted internet, so we decided to fresh install xp and completely remove Vista. We loaded xp, then clicked the C:/ drive (where vista was installed) and clicked format to cleart the partition. It errored part way through, so we cancelled and tried installing XP normally. Part way trhough installation, it errored saying it couldn't replace certain .dll files. It did like 100 of these. After canceling all of them and it finished, xp didn't load. At that point, now neither partitions will load. He can't install any OS higher than NT now ( which still wont connect to the internet). So, we tried a new harddrive. It errors at the same time with the .dll files. HELP!!!

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