First IE an OE are hosed, to fix this problem you need to reinstall both and to make your pc think they are not installed follow the instructions below. This info comes from, How to Reinstall or Repair Internet Explorer and Outlook Express in Windows XP, Microsoft Knowledge Base Article ? 318378? When all this is complete run sfc /scannow, in the run box, you will need to your xp cd for this.
Remember to back up your reg before you begin.
To reinstall Internet Explorer 6 browser component on Windows XP,,
To reinstall Outlook Express 6 on Windows XP
type regedit in the run box then,
use the following registry key: for Internet Explorer 6
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{89820200-ECBD-11cf-8B85-00AA005B4383}
This key is the only one with a plus sign next to it.
Click the folder itself and on the right side of the screen right-click the IsInstalled (REG_DWORD) value, and then click Modify. Change the value data from 1 to 0, and then click OK
Then go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{44BBA840-CC51-11CF-AAFA-00AA00B6015C} Click the folder itself and on the right side of the screen right-click the IsInstalled (REG_DWORD) value, and then click Modify. Change the value data from 1 to 0, and then click OK
Quit Registry Editor, and then reboot and say yes to clean up your personal settings for for both progs on reboot. Then download and install Internet Explorer 6 and Outlook Express 6 from http://windowsupdate.microsoft.com/ , or http://www.microsoft.com/windows/ie/default.asp
This should fix the problem
