After launching chem3D, no matter what I do, I get an error that the elements.tbl cannot be found.
In Chem3D 8, the elements.tbl is located in the C3D Items folder. This folder should be located in the Chem3D folder (default path is: C:\Program Files\CambridgeSoft\ChemOffice2004\Chem3D\). If it is not there, search for it on your hard drive. When you find it, move it to the Chem3D folder, and relaunch Chem3D. If the problem still occurs, make sure the C3D Items folder has 63 files in it. If it is empty, you need to uninstall and reinstall or do a Repair using the installer to put the files back.
If that does not help, it could be that Chem3D has been set to look in for the C3D Items folder in the wrong location. You'll need to edit your registry to fix the problem. Please note that editing the registry incorrectly can cause your system or applications to be damaged and not work correctly, so please take care. Go to the Start menu and choose Run and type "regedit" (without the quotes). Click OK. This will open the Registry Editor. Expand the following folders: HKEY_Current_User\Software\CambridgeSoft\Chem3D\8.0\. Click on the General folder. Now on the right side of this window, you should see a "C3D Items Path" key. Delete this key. Close the registry editor, make sure a complete C3D Items folder is located in your Chem3D folder, and launch Chem3D.