Just a quick registry key to stop adobe reader from updating to 64bit
[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Policies\Adobe\Acrobat Reader\DC\FeatureLockDown]
“bUpdateToSingleApp” Dword32 and set this to 0.
Setting this will ensure that only upgrade to 64 bit is disabled. Let me know if this works for you.