looks like you have to use the original DVD to change the versio

fowlloing is I googled from microsoft:


If your CPU is capable of running a 64-bit version of Windows, but your computer is currently running a 32-bit version of Windows, you need to start, or boot, your computer using the Windows 7 installation DVD. For more information, see Start Windows from a CD or DVD.
Note
You can't use the Upgrade installation option to upgrade a 32-bit version of Windows to a 64-bit version of Windows 7, or to upgrade a 64-bit version of Windows to a 32-bit version of Windows 7. You'll need to choose the Custom option during Windows 7 installation. For more information, see Installing and reinstalling Windows 7.
http://windows.microsoft.com/en-us/windows7/Windows-installation-problems-frequently-asked-questions

所有跟帖： 

• 多謝各位了! -WVW- ♂ (0 bytes) () 01/11/2010 postreply 23:06:14