I'm new to, really, all statistical models and have done some fair research specifically on regression models. I have come across some questions that I seem to have a hard time finding a clear answer to. When doing a regression model (I'm using Excels built in data analysis tool) I am curious how accurate it may be compared to a regression from R-Statistics. If not much is different or should be the same, where do I move going forward with the data received from the regression report? i.e. What should be done with variables that have low p-values? Thanks.