try download it first http://www.google.com/search?hl=en&q=iertutil.dll+download&btnG=Google+Search&aq=1&oq=iertutil.dll+
Re installing the application may fix this problem. Or you can try this: 01. Restart the computer. 02. When the BIOS information is displayed, press F8. 03. Select Safe Mode with Command Prompt from the Windows Advanced Options and press Enter. 04. Select the operating system that you want to start in Safe Mode with Command Prompt and press Enter. 05. Insert the Windows XP installation CD-ROM in the CD drive. 06. At the command prompt, type CD /D %SystemRoot%\System32 07. Type ren iertutil.dll iertutil.old and press Enter. Ignore any error message. 08. Type <CD Drive:> and press Enter, where <CD Drive:> is the drive letter, followed by a colon, of the CD/DVD drive. 09. Type expand iertutil.dl_ %SystemRoot%\System32\Broiertutil.dll and press Enter. 10. Press CTRL+ALT+DELETE and select Shut Down using the TAB key. Press Enter. 11. Use the arrow keys to select Restart and press Enter. 12. When your desktop appears, open Windows Explorer and Internet Explorer. If you receive Explorer.exe has encountered a problem and needs to close or Iexplorer.exe has encountered a problem and needs to close, press More Information to verify the module name. If the module is iertutil.dll: 13. Open a CMD.EXE Window. 14. Type regsvr32 /s /u iertutil.dll and press Enter. 15. Type regsvr32 /s iertutil.dll and press Enter. 16. Shutdown and restart your computer. See if that works..
He cannot even boot up his pc, and he doesn't have the recovery/installation cd. What should he do? I really appreciate everyone's help with my friend's situation!
when you start the comp, how far does it get before it complains it can't open explorer.exe? If you've logged in by that time, and it's just an error box on a blue background, try pressing ctrl+alt+del. If you get task manager, you can go new task, open command prompt (type cmd in the run box) and work from there. once you get to the command prompt, try running this: sfc /scannow It might be able to fix the problem. But seriously, if you're out of your depth - take it to a shop. don't make things worse than they already are. lol.