Hi I have a Windows XP and i recently tried to install my updates, however, it failed to update my security update. It says,"Security Update for Windows XP (KB828741) unsuccessfully updated. Please Help!!

Try it in safe mode with all AV & Firewalls disabled.

Then if that doesn't help google "Security Update for Windows XP (KB828741) unsuccessfully updated" and check out the options.

BTW How can something unsuccessfully update?

Try downloading and installing it again. It has only been unsuccessful because the download itself has failed or been corrupted in transfer.