Remove IE Failed/Corrupted InstallationLocked
Someone asked a question about removing IE 6 from their system so they could restore a previous version. Since we know that this is not possible, there is one other solution that I have seen.
http://www.litePC.com has a product called IEradicator that strips IE 4 or 5 from Win9x. This removes it completely. They also have a product called 98Lite that removes IE from Windows and retains some of the funtions that are removed with IEradicator.
I have not personally tried this, but I have heard good things from people who have. Apparently IE is not as unseparably tied to Windows as we would be led to believe. I would consider removing it as a completely last-ditch attempt to recover a failed or corrupted installation.