If you want all of the bundled software, do a real upgrade1) restore your system back to the way it was
2) put in the windows xp pro cd and this time choose "Upgrade existing OS" and don't blow away the partitions
This is what I did, and now I am running XP pro but with my bundled software. You may need to get the AGP drivers as stated above, but it's not that difficult. If you have problems, you can always re-restore, so there is little risk.