Unable to Uninstall Program

Running Windows 98, IE 6, on IBM Aptiva, 400MH, 192MB RAM, about 50GB hard drive free.

During the installation of Encyclopedia Britannica, I received the message –
“Warning: Uninstaller setup failed to initiate. You may not be able to uninstall this product.”
The warning was well founded, although it gave me no opportunity to halt the installation. I am unable to uninstall. During the attempt(using Windows- Add/Delete Program), I received the message – “log file ‘C:\Program Files\Britannica\BCD2000mm.isu’ is not valid
or data has been corrupted. Uninstall will not continue.”
(The file – BCD2000mm.isu – is empty, 0(zero) bytes)
The procedure corrupted my OutLook Express program. I had to reinstall it, by reinstalling IE 6.0. I’d really appreciate some ideas on this.