Unlink Formula - slow calculation

Hi All,
Let's say I have 2 xls file (test1.xls & test2.xls); and test1 file referring the value from test2 file

TEST 1.xls

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To do the above actions, I created a macro, but excel always frozen for couple of seconds during cell value set (.Cells(X, Y).FormulaR1C1 = tempvalue); as it will check the value from test2.xls

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I've tried to unlink the file beforehand:

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as well as

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and

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But no luck, it seems XLS keeps linking to that page everytime I put value (either manually / by macro)

Any idea?, as it slows down my xls

Thanks