instead of setup, i get Opera window

[okwassup]

Have HTC pro with sprint , some cab files when i try to run from with in the phone memory card ,when open the file to install, i see several files in there including setup file , but that set up file has the logo of the opera browser , and if i click the set up , i get a white blank window after few seconds ., how and what i need to do to make the setup file do its work , and install.,
any help please.?