An inplace upgrade will fail to install if SP1 is on the computer, but not
on the install disk.
If you have not deleted the SP1 replaced files, you can uninstall SP1 and
then do the upgrade.
Otherwise, you may be looking at a clean install.

"Victek" wrote in message
...
I'm in a Vista group and thinking XP. There is no repair install
in Vista. The closest thing is an in place upgrade, but you need
a retail version. If your Vista DVD is OEM, you'll have to do
a clean install.

To do this, replace the single core CPU with the dual core CPU.
Start Vista, which will run, but with only one core active. From
Vista, run setup on the Vista DVD, and do an upgrade install.
Vista will replace its files while retaining your installed apps, and
previous settings. If all goes well, you will have an operational
multi-core system. It would be advisable to back up your system
partition before the installation. If the upgrade install fails, you
can restore your previous single CPU installation, or format
and do a clean install.

Besides installing a multiprocessor HAL for a dual core CPU,
Vista will also install a multiprocessor OS kernel.


Thanks again! Last question: My Vista DVD should work for the upgrade
install (it's not OEM), however it doesn't include SP1 which is currently
installed. Would I just install SP1 again after the upgrade? I do have
multiple image backups so I can take my chances, but it's nice to have
some
idea what to expect :-)