There is a section of code that looks like. // This gets run when we upgrade the reg ver # or we start from an empty rv = GetSubtree(Xpcom) if(NS_FAIL(rv)) return rv; RemoveSubTree(XpCom) AddSubtree(XpCom); The problem is that if the XpCom GetSubtree fails (because the reg is empty or incomplete) we exit out and won't nuke the Classes stuff or try to re-create the XpCon keys. Even if the GetSubtree fails, we should still try to re-create the base keys. The same goes for the Classes/CLSID stuff. This code looks like it's isolated to PlatformVersionCheck()

More robust error checking implemented by Nick87@hotmail.com the person who filed this bug.