My browser wont use adobe flash player

Hello,
i have two browsers : internet explorer 8 and firefox . few days ago , there was no connection at all , but later it fixed itself . but i realized that websites like :www.facebook.com or www.twiter.com wont work . they all said that i had to enable my java scripting . which by the way used to worked perfectely before . after trying so hard i managed to re-enable it . but then i found out that at the same sites and other games sites , no games or videos would work at all . it always gave me the same message : u need to install adobe flash player 9 .
which i already had . after a while i found out that firefox is working perfectly from the begining , it didnt ghave any problems at all , and that appaently the problem is is IE8 . and i dont know how to fix it . please help me
thanks