vista installation: clean install or install over xp?

[jamgyu]

my question is if i install vista over a previous install of xp without wiping the hard drive first or uninstalling xp, does vista keep the registry entries of all my programs so that i don't have to reinstall them?

would it be a better idea to just backup my main drive, format it, and do a clean install of vista?

i used the vista upgrade advisor tool from MS website and it says that most of my programs are vista compatible.

[Gee]

Always try to do a clean install whenever possible.

If you have the upgrade version of Vista. Then you can install over XP and it will maintain your settings. But it is always better to do a clean install.