How do I transform the geographic coordinate system?

[RickCheney]

My map has various data sources. Sometimes I get the following error:

"This coordinate system has a geographic coordinate system that differs from one or more data sources in the map.

Use the Transformations button to set or change these transformations"

For example, when I view the properties for the Data Frame, I get the error.  I understand that I can use the Transformation tool as shown in the attached image, but I'm not sure which settings to select.  I don't understand how to use the tool in general.

Any guidance or advice you can offer is greatly appreciated.

[DanPatterson]

Rick Cheney‌

Geographic datum transformations—Properties of maps | Documentation 

There is a Note in there that not all geographic transformations are installed and if one isn't offered, you can download it

Other links

Geographic Transformations (Environment setting)—Geoprocessing | Documentation 

And if you want to get everything into a common coordinate system, then use the Project tool and provide the transformation there

[RickCheney]

Thank you very much Dan!  I will look through the information at the links you provided.  I do want to get everything into a common coordinate system and the Project tool sounds like the way to do it. 

I am not familiar with the Project tool.  I tried searching ArcMap but I didn't find anything.  Where do I find the Project tool?

Also, I'm not 100% sure which coordinate system to use but I think I should use NAD83(CSRS98) ??  Is that correct, the map is for the area along the border of Minnesota and Ontario, Canada

[DanPatterson]

I don't use arcmap any more, but if memory serves

Arctoolbox, Data Management tools, Projections and Transformations, Project

The NAD83 thing with CSRS98 rings a bell, but as long as they are in the same one

[RickCheney]

Sorry for the delay in responding.  I will need a few days to study the information at the links provided. I'm still trying to figure out which projection (or whatever) to use. I will reply back with either more questions or to mark as answered.  Thanks again.