shockwave flash not working

hello, my adobe flash is not showing up in manage add-ons. We did not delete it and when I try to fix it  tells me that we have the latest version but the only thing I found was version 15.0.0.152. Browser is IE ,yahoo ,windows 8.1.It is supposed to be under shockwave in add-ons and it is not there. Help please. We use a gateway computer pc.