I had XP Home SP 2, then IE 7, then went to XP Pro.
The only XP updates showing in Add/Remove Programs are:
KB923789
KB915865
KB926239
Now these updates always fail:
Security Update for Windows XP (KB926436)
Security Update for Windows XP (KB890046)
Security Update for Windows XP (KB902400)
Security Update for Windows XP (KB918439)
Security Update for Windows XP (KB891781)
Security Update for Windows XP (KB920670)
Cumulative Security Update for Outlook Express for Windows XP (KB929123)
Security Update for Windows Media Player Plug-in (KB911564)
Update for Windows XP (KB910437)
Security Update for Windows Media Player 6.4 (KB925398)
Security Update for Windows XP (KB896358)
Cumulative Security Update for Internet Explorer 7 for Windows XP (KB947864)
Security Update for Windows XP (KB946026)
Security Update for Windows XP (KB941693)
Update for Windows XP (KB936357)
Update for Windows XP (KB927891)
Security Update for Windows XP (KB941644)
Security Update for Windows XP (KB873339)
Security Update for Windows XP (KB931261)
Security Update for Windows XP (KB924270)
Update for Windows XP (KB900485)
Security Update for Windows XP (KB896423)
Security Update for Windows XP (KB924667)
Security Update for Windows XP (KB911562)
Security Update for Windows XP (KB936021)
Security Update for Windows XP (KB911280)
Security Update for Windows XP (KB923980)
Security Update for Windows XP (KB893756)
Security Update for Windows XP (KB920685)
Security Update for Windows XP (KB933729)
Security Update for Windows XP (KB899591)
Security Update for Windows XP (KB901017)
Security Update for Windows XP (KB911927)
Security Update for Windows XP (KB931784)
Security Update for Windows XP (KB928255)
Security Update for Windows XP (KB937894)
Security Update for Windows XP (KB923414)
Security Update for Windows XP (KB885836)
Security Update for Windows XP (KB885835)
Security Update for Windows XP (KB943460)
Security Update for Windows XP (KB927802)
Security Update for Windows XP (KB927779)
Security Update for Windows XP (KB899587)