My machine is much older -- Windows XP Pro.  I've been looking for the installer but now think I was thinking about Adobe Reader and NOT Flash.  The reader DOES have a Setup.exe nested on the computer.  Does your SysWOW64 have an Install program file?  The 'WOW64' makes me think there maybe different versions of Flash.  32 and 64?

Might be you'll have to download the installer using one computer installing the software from a disc or portable device.  Did you get Poser 8 on disc?  Maybe they included Flash?  I did look at my Add and Remove programs and REMOVE is the only option.  I was hoping they might include a REPAIR function.

Wish I could be more help.
Best Wishes,
Rªnce