Yes, you need to keep every one of those. You don't need to keep the uninstall files if things seem to be working well, but you need to manually delete those. Using the Add/Remove Programs tool will just remove the update, and with a few exceptions, only service packs are cumulative.
Looks like in the add/remove file cleanup area that I have about 30-40 Windows XP "security updates" and "hotfixes". Do I need to keep all the old ones or just the most recent version? I didn't know if each fix is seperate and needs to be kept, or if each update includes all of the previous updates?
Will it even help my system at all to remove the old ones? Thanks!