I just upgraded from dMC R13.5 Ref. to R16.6 Ref.
I am unable to get R16.6 to install.
[dMC-R16.6-Ref-Registered.exe (35,430,640 bytes)]
Each attempt goes from a pop-up saying:
"Installer
Processing Installer"
to two Windows pop-ups saying:
"C.tmp-dMC-Ref-Registered-32bit.exe has encountered a
problem and needs to close. We are sorry ..."
(Each attempt creates newly named files in %TEMP%.)

I uninstalled R13.5 first, before trying the R16.6 install.
* Though installing R16.6 fails, re-installing R13.5 does not.

I am installing from Safe Mode.
There is no security software running.
The installer *is* able to access my %TEMP% folder.
Each install attempt writes 2 files, of the form:
C.tmp-dMC-Ref-Registered-32bit.exe (17,754,864 bytes)
spiC.tmp (16,919,457 bytes)
No disk space errors; C: has >= 11 GB of free space.

The target system is Windows XP SP3, 32-bit AMD, 1 GB RAM.
It has all the updates that Microsoft offered for XP.
(I use this older system for a few dedicated purposes.)

I have searched the forum and read other accounts.
None I've seen so far have matched or solved my issue.

Again -- key -- R13.5 *will* install, R16.6 does not.
What dependencies does R16.6 have that R13.5 does not?