Error Message During Windows XP Update

When trying to update Windows XP I get the following error message:

"IEXPLORE.EXE - APPLICATION ERROR "
"The instructions at "Ox0469410a" referenced memory at "Ox04e4ac08" The memory could not be "read ". Click OK to terminate this program "

Unable to update XP and I get this message repeatedly.

Further, although IE 8 is not my default browser, whenever I turn on computer I get IE 8 windows asking me if I want to return to last page or to start page.

I uninstalled and reinstalled IE 8 -- not knowing what else to do -- but same problem. HELP! Thanks. I also notice that iexplore.exe runs even without using IE or Update.