Preferences gone!!!

I this is stupid but I accidentally deleted some of my preferences while trying to clean out some of my iMac. I tried to downgrade to 10.6.1 from 10.6.8 because it was giving me problems. I have a 3.06 GHz Intel Core 2 Duo if that helps. I am now using 10.6.1 and Safari 4.0.5. Everything runs great except for the fact that I can’t access the “Keyboard” in my System Preferences and strange things happen on my Safari when I hit certain keys on my keyboard. For example: I have to hit tab twice to go to the next text window and if I hit the spacebar while in a text window, the screen scrolls all the way to the bottom. The computer also remembers what I typed last in the windows and automatically defaults my curser to the end of what text is previously remembered in that window. When I try to delete it, it doesn’t let me delete anything because if I hit delete, it goes back a page. Very frustrating. And I haven’t set up my time machine so I can’t go back. If I try to access my “Keyboard” in the System Preferences, it crashes my System Preferences. Can someone please help me?

Bad things always seem to happen when downgrading. It's never a good idea to downgrade your version of OS X without doing a clean install. What kind of problems were you having that caused you to downgrade in the first place?

The only thing I can suggest is do a Time Machine backup first, erase your hard drive, and then reinstall Snow Leopard. Recover your data from Time Machine.

Very slow speeds and I went into the preference folder and actually got rid of files by accident. I have done this before but when I downgraded, it must have done something to my keyboard functions.

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Shouldn't all my preferences be restored once I re-install my os anyway?

A re-install should restore everything to the way it was before you downgraded. You will need to do that from your Snow Leopard DVD, Disk Utilities.