Start up with Shift key held down. Then remove the Finder Preferences file from the System Folder's Preferences folder.
If you have and know how to use ResEdit or a similar editing program you can just remove all 'sgci' resources from a copy of the Finder Preferences file and replace it. This latter approach preserves all other Finder preferences.
WARNING:
The instructions in this article refer to using ResEdit to alter your system software. Apple Computer, Inc., is not liable for any damage done to your software through the use of ResEdit to alter the software. The User Assistance Center phone representatives (at 800-SOS-APPL) do not provide technical support for ResEdit. It is supported by APDA. For contact information on APDA, search the Tech Info Library under "APDA".
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