The summary.
A STOPPED SERVICE PRODUCES SYMPTOMS WITH NO VISIBLE CAUSE
Many functions depend on background services. Check whether the relevant one is running.
MISSING OR WRONG RUNTIMES PRODUCE OBSCURE ERRORS
Check stated requirements before installing, not after it fails.
UNSUPPORTED SOFTWARE RECEIVES NO SECURITY FIXES
Once a weakness is published, automated exploitation follows within hours.
Identify which applications constrain your ability to upgrade — they determine how long you stay exposed.
Isolate unsupported software from anything that matters.
TEST SIGNIFICANT UPDATES BEFORE DEPLOYING THEM
Automate routine ones where the risk of delay exceeds the risk of the update. Never automate major version changes.
WATCH WHAT INSTALLERS ADD
Bundled software, changed defaults and browser extensions. Read the screens rather than clicking through.
LICENCE COMPLIANCE IS DEMONSTRATED BY RECORDS, NOT ASSERTION
Track what is installed, under what licence, how many, and with proof of purchase.
Unlicensed software is also a common malware vector.