Tidying and deduplicating files listed in a DataGridView
I found some code that you could tidy up a bit right here


    j = FileNames.Count
    i = 0
    Do
        str = FileNames(i)
        If str.Contains("-00-") Then
            FileNames(i) = RemoveChar(str, "-00-") ' RemoveChar is a function that replaces "-00-" with a "-"
        End If
        i += 1
    Loop Until i = j



that seems like a lot of work for such a simple task. 

use a for loop that goes from the base index to the FileNames.Count value.

Then use a Replace instead of creating a function that does a replace.  here is some code that does the same thing

keep in mind that a replace will only replace a string that it can find, so you don't have to check for the substring in your string before you call the Replace function on the string.

For i As Integer = 0 To FileNames.Count
    FileNames(i).Replace("-00-", "-")
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