Today I lost my Windows Live Writer. I was doing a Windows Live update of installed WL applications. The update performed an uninstall first and install after. But the install failed and fails with an error 0x80070643. Of course it didn't rollback the original installation.
Quick googling for the solution doesn't help as well. Great error message and hidding installation log file is a great feature, [MS]. Damn, I'll just use Sysinternals to figure out what goes wrong.