I installed the Update RollUp on my personal Windows XP HOME machine because it showed up in Windows Update. It does change the numbers for your currently installed patches and lists them ALL as a single 826939 Hotfix in "Add/Remove Programs". It does make it look a little cleaner but if you have all the updates included in the link below, it's not a required download. AFter installing the RollUp, you can choose to uninstall the RollUp, and all the separate patch numbers will be restored. Make sure to read about it in the link below. Read everything in it and it should help.:
Update Rollup 1 for Windows XP Is Available
Hope this helps.
If I have all the security updates for XP except Update rollup 1 for Windows XP, do I need this? Is there something different here than in the individual updates that are already on my computer?