Soop1,
Well, if you have a bootable "Classic" CD (MacOS 8.6 > 9.2.2 or one of the utilities like Norton), you can boot to this CD and have access to the OSX files. However, you MUST be careful when deleting files...you don't want to delete a necessary OSX file.
When I boot to 9.x on my Wallstreet from my HD and open the HD icon, I see the Applications folder and Applications (Mac OS 9) folder; the latter is present if you have 9.x installed. Open the Applications folder and drag iTunes to the Trash; restart to 10.x and see if the issue is solved.
If you can startup to OSX in Safe Mode/Safe Boot, you should also be able to delete the troublesome files.
http://docs.info.apple.com/article.html?artnum=107392
If all else fails, you may have to reinstall the OS:
http://www.macfixit.com/article.php?story=20060322080433175