Newer versions of regtlib.exe have a -u switch that will let you unregister type libraries. If your version of regtlib.exe doesn't support this switch and you can't find a newer version, you can also do it with this utility:
http://www.vbaccelerator.com/codelib/tlb/vbregtlb.htm
Or this utility:
http://www.mvps.org/btmtz/_misc/regtypelib.zip
- Elton