BUG #16509: Unable to change from 32 bit to 64 bit

The following bug has been logged on the website:

Bug reference:      16509
Logged by:          Pierre Mantha
Email address:      thecobv@gmail.com
PostgreSQL version: 10.9
Operating system:   Windows 10 Pro
Description:

Hi

Noticed that we were running a 32 bit version.
Attempted to install 64 bit version.
Deleted all directories, all entries from registry - expect some temp that
would not allow deletion.
Rebooted
attempted to run installer for 64 bit version and keep getting this
message:
" You already have a 32 bit installation of pgAdmin4, Please uninstall this
before installing the
64 bit version".

So basically your uninstall process does not clear ALL values as this is
litterally impossible to do.