vtam5789老兄看過來，關於XP和Vista共存的問題：

你說“先裝vista,後裝xp...再修改bootrecord,但是x64 boot不了”，那是你安裝的順序顛倒了，微軟關於Dual Boot有這樣一段話：

To resolve this problem, install the earlier version of Windows on the primary boot partition, and then install Windows Vista on a new partition. If you want to be able to start from more than one operating system, install the earliest version of Windows first, and then install the later versions in the order of release. For example, install the operating systems in the following order:
1. Windows 2000
2. Windows XP
3. Windows Server 2003
4. Windows Vista
Install each operating system according to the standard installation procedure.

Note Install each version in its own partition.


如果一定要先裝Vista的話，可以參見下麵給方法：

http://support.microsoft.com/kb/933179

http://support.microsoft.com/kb/555852

Good Luck！