Hi DD
Paste the following into a module of your main workbook.

Sub DoWhatDDNeeds5()
A = 1
B = ThisWorkbook.Name
C = ActiveSheet.Name
D = "Split " & A & ".xls"
E = 2
F = 10
Do Until Workbooks(B).Sheets(C).Cells(E, 1) = ""
D = "Split " & A & ".xls"
Workbooks.Add.SaveAs Filename:=D
Workbooks(B).Activate
Workbooks(B).Sheets(C). _
Range(Cells(E, 1), Cells(F, 8)) _
.Copy Workbooks(D).Sheets(1).Range("A2")
A = A + 1
E = F + 1
F = F + 10
Loop
End Sub

Activate the sheet that has the data, then run the code.
It will generate about 10 new workbooks called Split 1, Split 2 etc, each
containg 20,000 rows of data, and leave them all open. You need to save them
to wherever you want. Your original workbook will be unaffected.
Note: If your computer complains about not having enough memory to have all
the workbooks open, let me know.
Also, if you need header rows in each workbook, we could do that too.

Regards - Dave.

Oops, sorry. I sent the the wrong code. I didn't have 200,000 lines of data,
so I made up a miniature version. The code for the real thing is:

Sub DoWhatDDNeeds5()
A = 1
B = ThisWorkbook.Name
C = ActiveSheet.Name
D = "Split " & A & ".xls"
E = 2
F = 20000
Do Until Workbooks(B).Sheets(C).Cells(E, 1) = ""
D = "Split " & A & ".xls"
Workbooks.Add.SaveAs Filename:=D
Workbooks(B).Activate
Workbooks(B).Sheets(C). _
Range(Cells(E, 1), Cells(F, 8)) _
..Copy Workbooks(D).Sheets(1).Range("A2")
A = A + 1
E = F + 1
F = F + 20000
Loop
End Sub