Visual Studio 2015 Installation Problems

I am having major problems with installing Visual Studio 2015 that I have been dealing with since its release on Monday. I uninstalled Visual Studio 2013 Ultimate and installed Visual Studio 2015 Enterprise and this happened:

The installation has not only partially failed, but Visual Studio is not even completely installed, and devenv.exe is missing from the folder. Is there a way that I can wipe everything related to Visual Studio from my machine, including plugins, extensions, etc. and start fresh? I'm trying to run an installation repair at the moment, but I don't believe it is going to get me anything.

I'm extremely frustrated to the point of anger at the moment, so please try to be patient with me.

UPDATE: Visual Studio is now working, but I still have one problem with the Windows Phone SDK not installing. Any ideas for a fix?

Here is what the log file has to reveal on the failed Windows Phone 8.1 SDK installation.

[0120:18C0][2015-07-23T15:01:25]i000: MUX:  P5 - Windows Phone 8.1 SDK
[0120:18C0][2015-07-23T15:01:25]i000: MUX:  P6 - Install
[0120:18C0][2015-07-23T15:01:25]i000: MUX:  P7 - 0x80070643
[0120:18C0][2015-07-23T15:01:25]i000: MUX:  P8 - There is a problem with this Windows Installer package. A program required for this install to complete could not be run. Contact your support personnel or package vendor. 
[0120:18C0][2015-07-23T15:01:25]i000: MUX:  P9 - 

As the Windows 10 update caused more problems with my computer, I ended up reimaging my machine and starting fresh. When the time came for me to install Visual Studio 2015, everything worked perfectly. I never found out what the problem actually was, and I am aware that this is not very helpful for those who do not want to reimage the machine.