I have noticed that the link HP Softpaq Download Manager (www.hp.com/go/sdm) leads to:
Oops. We can't find that page for you.
It turns out that the correct location of the HP SDM is:
http://whp-aus1.cold.extweb.hp.com/pub/caps-softpaq/cmit/HP_SDM.html
There you can select the latest version or earlier versions of the SDM Softpaq Exe and the corresponding Release Notes.