Adobe AIR Installation failure - due to .msi problems?

Hola. Been trying to get AIR updated from version 3.1.0.4880, it may be one of the issues preventing me from playing Mass Effect 2; so I attempted to download the newest version (Currently 18.0.0.180).
However, when installed normally, or 'silently' through command prompt, it fails and says I may need to contact an administrator. (I'm the only user on this PC, it is my own.)
Posted below is the install.log in its full transcript, I have no earthly idea what's going on. Any help is much appreciated.

[2015-07-14:02:20:38] Runtime Installer begin with version 18.0.0.180 on Windows 7 x86

[2015-07-14:02:20:38] Commandline is: -silent

[2015-07-14:02:20:38] Installed runtime (3.1.0.4880) located at c:\Program Files (x86)\Common Files\Adobe AIR

[2015-07-14:02:20:38] Starting silent runtime update. Updating runtime from version 3.1.0.4880 to version 18.0.0.180

[2015-07-14:02:20:39] Installing msi at c:\users\indirect\appdata\local\temp\air8249.tmp\setup.msi with guid {31B9D218-FED2-4C6C-B19F-7294FFC130B0}

[2015-07-14:02:20:51] Error occurred during msi install operation; beginning rollback: [ErrorEvent type="error" bubbles=false cancelable=false eventPhase=2 text="1603" errorID=0]

[2015-07-14:02:20:51] Rolling back install of c:\users\indirect\appdata\local\temp\air8249.tmp\setup.msi

[2015-07-14:02:20:51] Rollback complete

[2015-07-14:02:20:51] Exiting due to error: [ErrorEvent type="error" bubbles=false cancelable=false eventPhase=2 text="1603" errorID=0]

[2015-07-14:02:20:51] Runtime Installer end with exit code 7