Are you using windows? if so, if it is home version...then on your task bar look for the explorer file folder.. open it then expand your local disk (C:)...then go down to windows and expand it. Look down until you see the system32 folder...expand it....then go down to macromed....... expand it.....then look ofr the flash folder.
For 64 bit windows it is the same but instead of system32 look for syswow64 folder.
If your using an Apple then That wont be right.
If you really don't know what you are doing then leave your Maxthon3 alone as the version that came with it should work fine.