chas638 said:
First, can I upgrade to Vista with the full installation program without
losing all my programs or do I have to do a clean install?
Not sure what you mean by "with the full installation program". Depending
on what version of XP is on the sytem and to what version of Vista you wish
to go to, it might allow an in place upgrade (programs and data retained),
or it might require a custom (clean) install where they are not migrated.
See this link for info on the upgrade paths. Green dots mean in place
upgrade is supported, yellow means only custom install.
http://www.microsoft.com/windows/products/windowsvista/buyorupgrade/upgradepaths.mspx
On OEM version can only do a custom install.
If I create another partition, can I install and run both XP Pro & Vista
Ultimate on the
same machine selecting one or the other at boot up.
If the Vista was an upgrade version and XP was the qualifying OS used for
that upgrade, then no. The Vista license prohibits running both at the same
time. If Vista is uninstalled then the XP license can be reused.
If the Vista version is the full retail version or an OEM, then yes you can
dual boot with XP since XP is not needed as a qualifying OS for the upgrade.
If not, can I go back to XP without losing everything if I don't like
Vista?
There is a KB article that describes how you can revert to XP from an
upgrade. If that doesn't work then to do this you would need to clean
install XP.
How to restore a computer to a previous Windows installation after you
install Windows Vista
http://support.microsoft.com/kb/927522/en-us
Clean Install Windows XP
http://www.michaelstevenstech.com/cleanxpinstall.html
Always, always have a full backup, and that advice is mandatory when
upgrading an OS. I recommend using a drive imaging program such as Acronis
True Image Home version 10 to image the XP installation to an external USB
drive before doing the upgrade, then if things don't work out it can be
restored quickly.