: It was one of the last versions users could "own" with a perpetual license rather than paying a monthly subscription fee, a fact that still sparks debate in tech forums today. A Digital Time Capsule
This often occurs if remnants of a newer Reader exist. Use the (official) to scrub all traces, then reboot and retry the 11.0.23 install.
If you absolutely need :
"Acrobat Reader cannot be installed in a 64-bit environment." Solution: Ignore this misleading error. Click OK and continue. It installs just fine on 64-bit Windows (it runs in the 32-bit subsystem).