If your PC is behaving properly you can remove the Windows hotfix backup files and their corresponding entries in Add/Remove Programs. Download, extract and run this little script click here
Create a system restore point first (WinXP) just in case anything goes wrong during the registry updating.
Alternatively, copy them to a CD, manually delete them from the \Windows folder but leave the now orphaned Add/Remove Programs entries intact. Do not delete the $hf_mig$ folder, only the $NTUninstallKB….. folders.