I just bought some ram at best buy for $5 for my brothers HP 6649F. I bought 128MB of Generic PC133 ram, but the back of the box says that computers that use Intel 810 or 810e should only buy PC100, because PC133 is not backwards compatible with PC100. Do I need to return this ram? It is only $5, but I don't want to have cheap ram sitting around for no reason. Any help is appreciated.