Very interesting.
1) "C:\Windows\SysWOW64\Macromed\Temp" exist with an empty folder, no data.
2) There is also a folder "C:\Windows\SysWOW64\Macromed\Flash" with 14 files (FlashPlayerPlugin_32_0_0_142 etc...), new from the date when I got the message in #1.
3) A longer search found in IrfanView's plungin.txt an entry flash.dll
4) IrfanView reports 2 Flash-PlugIns from Adobe & Macromedia; don't know where they com from, never used that.
5) "installflashplayer.exe" doesn't exist here.
6) system control shows an old version of Flash player, never used that.
thx