migration Windows xp with SP2 to another PC with differet hardware.

Acronis TrueImage Server with Universal Restore:
http://www.acronis.com/enterprise/products/ATIESWin/universal-restore.html

This will do the job a treat.

Workstation may be a better option - you can use Universal Restore with that as well:
http://www.acronis.com/enterprise/products/ATICW/

i.e.
http://www.acronis.com/enterprise/products/ATICW/universal-restore.html

Thanks,

You means I can download trial edition and that that function well? of course I prefer free software.

You get what you pay for. This is excellent software that will be of great use in the future.
As far as I know - you cannot obtain a trial version of Universal Restore - so unless you were restoring the data to a computer that had exactly the same hardware - then the trial of Workstation would be useless.

Thanks,

Can Vista auto detect the new hardware and make the OS startup without any problem? What I can think is upgrade to Vista first and then change a new PC.

Thanks all,

I think I have to reinstall everything if I port it to different hardware platform.

This was always the best way of doing it.
But with some patience - it can be done with the Acronis product.