OE and IE are tied quite tightly together, so it isn't suprising that you are having a problem with both.
I would be inclined to back up any emails, back up IE favourites, then remove them (Control Panel > Add / Remove Programs > Windows Components).
Reboot, then re-install in the same way. You will need the XP installation media to do this, BTW.
If it all works, great. Then don't forget to update all the MS patches!
If not, remove them and move to an email program and browser that work better - e.g. Thunderbird & Firefox.
SD