Installed Acrobat DC Pro and can't unistall Acrobat 9.5 Standard

OK.  Going to assume that this is a Windows based machine...

Unlicense Acrobat DC (so you don't 'burn' a license.)

Uninstall Acrobat DC (Programs & Features).

Reboot

Try uninstalling Acrobat 9 (again, Programs & Features).

Download and run the Adobe Reader & Acrobat Cleaner tool - Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs

Reboot.

Check to see that A9 and assorted bits are actually gone.

Try installing ADC.  If it works, license the installation.

Another tool I've had a great deal of success in cleaning up after errant installs and apps is Priform's CCLEANER - CCleaner - PC Optimization and Cleaning - Free Download .  Use at your own risk, but like I said - I've had a great deal of luck with it.

Hope this helps.

Doug