I sorta meant that as a test. I don't know how many records you are working with but some testing would find the answer to how they need to be changed in order to fit into SQL. I have just done a ToUpper() and they went right in, but it would depend on the format you have. For instance do they look like this:
{1C285071-CB16-496a-B800-C9C1FC4DAA3C}

I find it very interesting about the 4 in the 15th position Charles mentioned. I had never heard of that and don't know what that means, but I see it holds true.
Tim

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>So you are saying execute a ToUpper() on each guid type column in every row before I call the Bulk Copy? I guess that means leave the fox table type as C(36) and not a varbinary.
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>That could be really slow depending on the number of guid columns times the number of rows in each data table. I was hoping more to know which data type I can leave the fox tables guid columns in and have it move from fox to C# dataset to Sql table without any major hoops. I guess there is none.