just install using the windows 7 disk, if it was working in xp then it will work in 7.
i have made this upgrade personally and used the machine for months.
gx280 / p4 3.4ht / 2gb / hd2400 / win7-ult x32.
all drivers install upon os installation even all on-board.
just in case have an active internet connection during install so it can get to download any install updates and drivers.