A later version of Vagrant is installed. Please remove this version first. Setup will now exit.

I'm trying to downgrade my Vagrant install to 1.9.7 from 2.0.1 because when I upgraded to 2.0.1 I lost the bash prompt after ssh'ing into my Vagrant box (ubuntu/trusty64) using Cygwin.

### Vagrant version
2.0.1 (uninstalled via Add/Remove Programs and removed .vagrant.d directory)

### Host operating system
Windows 10

### Guest operating system
N/A

### Expected behavior
The uninstall should have removed all traces of Vagrant 2.0.1 and I should be able to install an older version of Vagrant.

### Actual behavior
When trying to install both 2.0.0 and 1.9.7 I get the error message: A later version of Vagrant is installed. Please remove this version first. Setup will now exit.

### Steps to reproduce
1. Install Vagrant 2.0.1
2. Uninstall Vagrant 2.0.1
3. Install any prior version of Vagrant (at least 2.0.0 or 1.9.7 were the two I tested)

In all of my tests I'm using the x86_64.msi installer.

I also tried reinstalling 2.0.1 and then uninstalling it again thinking something didn't get completed the first time it uninstalled, but still wasn't able to install a prior version.