I had an issue once where a certain configuration of Microsoft .NET programs wouldn't let me install something similar, with the same generic error code 643. I ended up formatting the computer (because of my own stupidness at the time) and re-installing again.
But this is a known issue and has a Knowledge Base Article
Taken straight from that article:
To resolve this problem, you must fix the MSI software update registration corruption issues, or uninstall multiple versions of the .NET Framework by using the .NET Framework Cleanup Tool, and then reinstall those components.
The article then walks through the two methods above. Hope this helps!