If you remove them from Add/Remove, you will remove the hotfix itself. The hotfixes store their backup files (what they replaced) in the Windows folder. Each subfolder looks something like:
$NtUninstallQ322011$
These are hidden folders. If your system is stable, and you don't need to remove any of the hotfixes, you can delete these folders and the Add/Remove Programs entries. See
www.dougknox.com, Win XP Utilities, Remove Hotfix Backup Files for an automated tool to assist with this.