Install BootCamp drivers in Windows 10 to fix bluetooth and keyboard issues
Unless you have one of the very early Intel Macs, the Windows Support Software is suppose to be available to the Windows installer during the installation process. This is so the Windows installer can access any drivers included in the Windows Support Software that are not already part of the installation software provided by Microsoft.
If you have an older Mac and are using the current Windows 10 release, then most likely any required drivers in the Windows Support Software will be already included in the Windows 10 release. In this case, having the Windows Support Software available to the Windows installer during the installation process may not be necessary.
Once Widows is installed, additional software can be installed by executing the Setup.exe application included in Windows Support Software. Afterwards, additional software can be installed through the Apple Software Update application. Windows Update may also provide software.

Your question indicates you downloading the Windows Support Software after installing Windows. You can post a comment, if I am wrong about this.

My best guess would be you used the Boot Camp Assistant on a Mac of a different year and/or model to download the Windows Support Software. This is a common mistake. If you did this, then most likely the wrong Windows Support Software was downloaded.
The other possibility is your Mac Pro is older than the 2013 model. In this case, Apple does not support Windows 10 for your Mac. If this is true, then you should have included this in your question.

The fact that you do not mention running Setup.exe, but instead mention BootCamp.msi, indicates that you did run Setup.exe which terminated early with an error message. The message either states lack of support for Windows 10 or you have the wrong version of Boot Camp.