Can't complete installation; can't uninstall

[nightstitcher]

Just hooked up my DVD writer, and started try ing to install DVD MovieFactory 3.5SE. It want part way & hung up. After rebooting, I tried to reinstall, and it refused, demanding I uninstall first. Tried that via add/remove programs (Win 98 SE), that wouldn't either, giving a lengthy crash message. Before I restore my C: drive from the image backup I made prior to installation (a lengthy process), are there any other ideas? Should I delete Ulead registry keys, for example?