I cant install itunes it keeps saying this error?

what do i have to do when the error pops up then it rolls back action when the installation is complete and i click on itunes it says ipod can not be used because the requirements were not installed please remove and install again ive done that bout 5 times now and it still doesnt work then i started searching the web and they said to install VC runtime and the same error showed up again its to do with microsoft embly thing i dont know but please help me ?????????