"copy was older"
This is because windows will have been updated to at least SP2.
your new version will need to be update.
"Can't get any sound to work on it"
You need to load all the drivers for your sound card motherboard graphics etc. into the new version.
"how do i get rid of the other partitions?"
you will need a third party program to adjust partitions such as Partition magic 8.
The easiest way may be to start from scratch, boot from the XP disk and delete all partitions and reformat the drive, and then reinstall XP
install drivers and then update to sp3.
Make sure you have all your drivers before you start.