You can boot into Single User Mode to delete the Finder preferences file.
Run FSCK first;
To run fsck, you first need to start up your Mac in single-user mode. Here's how:
1. Restart your Mac.
2. Immediately press and hold the Command and "S" keys.
You'll see a bunch of text begin scrolling on your screen. In a few more seconds, you'll see the Unix command line prompt (#).
You're now in single-user mode.
Now that you're at the # prompt, here's how to run fsck:
1. Type: "fsck -y" (that's fsck-space-minus-y) (without the quotes)
(If you're running Panther, v 10.3, then type this "fsck -f"
2. Press Return.
The fsck utility will blast some text onto your screen. If there's damage to your disk, you'll see a message that says:
***** FILE SYSTEM WAS MODIFIED *****
If you see this message--and this is extremely important-- repeat running fsck. It is normal to have to run fsck more than once -- the first run's repairs often uncover additional problems..
When fsck finally reports that no problems were found, and the # prompt reappears:
3. After fsck indicates the disk is OK (No problems found), at the prompt, type the following exactly as written:
/sbin/mount -uw /
then press Return. Be sure to note the spaces in this command: there is a space after mount and a space after -uw. This command mounts the file system so you can delete the Finder preferences.
At the prompt, type the following exactly as written:
rm /Users/your_user_name/Library/Preferences/com.apple.finder.plist
where your_user_name is your "short" user name on your computer. Then press Return. The preferences file on your ID are now deleted.
Finally, at the prompt, type reboot and press Return to restart in Mac OS X.